New York HVAC license: what NYC, Westchester and Long Island require, and what your business needs in the first 30 days

Published November 3, 2026 · Rules checked November 3, 2026

• Free. The full 30-day checklist is on this page. The printable version (PDF, Word or Google Docs) comes by email.
• Deepsel is our product: free estimate, invoice and scheduling software for contractors (scheduling, quotes, invoicing, card payments). The section before the FAQ says where it fits and where it doesn't.
• Not legal advice. Every rule here links to the code section, rule, form or case it comes from. Ask the licensing office or a New York attorney before you bet a job on my reading.

New York has no state HVAC license. I found no state board or statute that licenses HVAC contractors, and the state's building codes division says plainly that "licensing of contractors or electricians" isn't handled there.³³ The license comes from where the job is. In New York City, the Department of Buildings (DOB) issues mechanical permits only to a registered general contractor, homes need a home improvement license from the Department of Consumer and Worker Protection (DCWP) on top, and gas, oil and wiring each go to their own licensed trade.^{1, 3, 8} Westchester County has licensed HVAC work since July 2025, Nassau and Suffolk license it as home improvement, and Buffalo has a heating contractor license.^{19, 23, 27, 31}

You're getting this because DOB lists your firm as a registered general contractor, which is how HVAC companies hold mechanical permits in the five boroughs. Most of you are based on Long Island or in Westchester, and that registration does nothing for you at home: each county licenses separately. In December 2025 an appeals court threw out an HVAC installer's lawsuit over a house in Nassau because it had no Nassau license, and the licensed subcontractor who did the install didn't save it.⁴⁶ Below: what applies in each place, what your work covers and what you sub out, the refrigerant and lead rules, permits, a "can I take this job?" table, what crossing the line costs, and a 30-day checklist you can print.

No state HVAC license: what applies instead, place by place

Sources for the table: New York City,^{1, 6, 10} Westchester,^{19, 20, 21, 22} Nassau,^{23, 24, 26} Suffolk,^{27, 28, 29, 30} Buffalo.³¹ The Attorney General's list of places that license home improvement contractors adds Putnam and Rockland counties.³²

NYC HVAC license: what your DOB registration does, and what it doesn't

DOB puts it in one line: "Permits for mechanical systems work are only issued to the Registered General Contractor (GC)." The next sentence matters as much: "renovations and alterations of 1-, 2-, 3-, 4-family homes and individual apartment units require a Home Improvement Contractors (HIC) license issued by the Department of Consumer and Worker Protection in addition to the GC license."¹ (DOB's Contractors page also lets some alteration permits go to a firm with only an Insurance Tracking Number or a Safety Registration Number, so the line isn't quite as hard as that first sentence.⁶) On a permitted HVAC job the paperwork runs like this: the owner hires a professional engineer or registered architect to file plans, and the permit goes to you as the registered contractor.²

What the registration took, and what keeps it

• $300, renewed every three years for $240. Operating capital over $25,000 (three months of bank statements ending at $25,000 or more), a $1 million general liability policy, workers' comp and disability insurance, and a background check. No exam.⁶ Let a policy lapse and the registration is short of what it rests on.
• The application names "the officer, principal or director of the applicant who is primarily responsible" for following the code.⁶ That's the nearest thing NYC has to an HVAC qualifier. I found no rule stopping that person from serving two firms.
• Your office. DOB's mechanical page says "The GC must have a place of business in New York City as per §28-401.18," and that section requires an established place of business with a city address.^{1, 7} DOB's registration guidelines, though, only ask applicants who live outside the city for an agent to receive legal papers.⁶ If your only office is in Hicksville or White Plains, ask DOB's Licensing unit which one applies to you before your renewal.
• DOB's page also says "All licensees shall include their license number and business information on trucks, business cards and advertisements."¹ I didn't find that sentence in Article 418 itself, but it's DOB's instruction, so letter the truck.

The DCWP license for HVAC work in NYC homes

The City's definition of home improvement says that "without regard to the extent of affixation," it includes "the installation of central heating or air conditioning systems." A "building" there has no more than four homes, but a contract with a co-op or condo owner or a tenant counts whatever the building's size. No one may "solicit, canvass, sell, perform or obtain a home improvement contract" without the license, and no other license or authority stands in for it.⁸ Your DOB registration doesn't exempt you either. The exemption is for trades the law tests for competency, such as plumbers and electricians, working only within their license, and the registration has no exam.⁹

• The $200 line. Jobs where "the aggregate contract price for all labor materials and other items is less than two hundred dollars" are exempt, unless the job is part of something bigger or split up to stay under.⁹ A diagnostic with nothing else sold usually stays under it. Add a capacitor and a contactor and the ticket often doesn't. As I read the definition, which starts with "construction, repair, replacement," a furnace repair in a house is home improvement too.
• Getting it. An owner, partner, officer or 10% shareholder passes DCWP's exam (30 questions, 21 to pass). Fingerprints for the principals. Join DCWP's Trust Fund for $200 or post a $20,000 surety bond. A workers' comp certificate naming DCWP, or the state's exemption. EPA lead certification or a signed statement that you don't need it. A sales tax ID.¹⁰
• Cost and dates. $200 for two years, and every license expires on February 28 of an odd year. File between now and February 28, 2027 and you pay $50 for a license ending then, or $250 for one running to February 2029.^{8, 10}
• Subs. DCWP's inspection checklist says every subcontractor you use must hold the license. Licensed plumbers and electricians working inside their license are exempt under the code.^{10, 9} My NYC general contractor license article goes through the license in more detail.

Who holds what, and being someone else's license

In New York the HVAC licensing sits with the business: the DOB registration, the DCWP license and the county licenses are all issued to the firm. People come in through the trades and the exams. NYC's master plumbers, master electricians and oil-burning equipment installers are licensed people, and everyone else works "under the direct and continuing supervision" of one.^{11, 13, 14} DCWP's exam is taken by an owner or officer, Nassau wants five years' experience from one principal, Suffolk tests the individual applicant, and Buffalo's exam goes to a named officer or regular employee.^{10, 24, 27, 31} I found no rule in any of these saying how long a firm has to replace that person if they leave. Westchester wants written notice within 10 days of a change in ownership, management, name or location.²⁰ None of them can be lent out. Westchester's license "shall not be assigned or transferred," Nassau's rules say "No contractor shall permit his license and/or license number to be used by another," and in NYC only a registered firm may call itself a registered general contractor.^{20, 25, 6} Someone will still ask to pull an NYC permit through your registration. One owner described starting out that way: "Was already doing sub work before I quit my day job “under someone else’s license”" (r/HVAC). If you agree, your firm is the contractor of record on a job you don't run. A later article covers that deal.

What NYC splits off: gas, oil, the circuit and the thermostat

New York City has no HVAC installer license, so the work an HVAC company does in other states is split between your registration and four licensed trades. DOB says it directly: parts of mechanical work, including "piping, fuel-burning equipment, ductwork, air-conditioning equipment, electric wiring," "can only be performed by designated Skilled Trades or Contractors with specialized licenses."³

• Gas: a master plumber. Plumbing work includes gas piping, and only a licensed master plumber, or someone under their "direct and continuing supervision," may do it.¹¹ The people working under the plumber on gas need DOB's full or limited gas work qualification.¹¹ Swapping a gas furnace or boiler is plumber's work too. The code lists the in-kind replacement of gas appliances among a master plumber's limited plumbing alterations, and lets a licensed plumber replace a gas furnace or boiler of 350,000 BTU or less in a building of five families or fewer without a permit, if the appliance shutoff valve isn't moved and the job goes on the plumber's monthly report.¹² So on a furnace and AC change-out in Queens, you set the coil, the condenser and the ductwork, and a master plumber sets and connects the furnace.
• Oil: an oil-burning equipment installer. "It shall be unlawful to install oil-burning equipment in the city unless such work is performed by or under the direct and continuing supervision of" a licensed oil-burning equipment installer, and that license covers "burners, boilers and generators."¹³ Replacing an oil burner, boiler or a tank of 330 gallons or less is filed as a limited oil-burning appliance alteration by that installer.^{12, 3} The rule is written around installing. Cleaning and adjusting an existing burner isn't installing, as I read it.
• The circuit and disconnect: a master electrician. Electrical work takes a licensed master electrician, on their own electrical permit, and DOB names "boiler line voltage work and controls" as electrician's work.^{14, 3} My NYC electrical license article covers the electrician's side of a condenser circuit.
• The thermostat: probably the electrician too. Low-voltage wiring under 50 volts needs no permit, but the code reserves "a point of connection to or interfacing with a control circuit that activates light, heat, or power circuits" to master and special electricians.¹⁴ A thermostat is exactly that connection, as I read it, and I found no HVAC carve-out. Ask DOB before you put thermostat swaps on an NYC price list.
• Large refrigeration: FDNY, for the owner. "Any refrigerating system requiring an FDNY permit must be under supervision of" a Q-01 Refrigerating System Operating Engineer while it runs, and the certificate is tied to the premises.¹⁶ That's the building's operator, not your installer license.

Ductwork, air handlers, condensers, mini-splits and rooftop units are yours under the registration, with a permit where one is needed (the permits section below). Running a condensate line is mechanical work. Tying it into the building's drain piping looks like plumbing work to me, since plumbing work covers "any piping system referred to in the New York city plumbing code."¹¹

Westchester County HVAC license (since July 2025)

Westchester's HVAC license is its home improvement license. The county added HVAC and power washing in a June 2025 law: "as of the first week of July 2025, all HVAC professionals and power washing operators must also be licensed through the County's Department of Consumer Protection."¹⁹ The law now lists "r. HVAC" among the kinds of home improvement, which covers a "private residence, townhouse, condominium, apartment, or dwelling place of not more than three units."²⁰

• Who needs it. Any person or firm doing, advertising or offering home improvement in the county, including anyone who, for a fee, arranges for other contractors to do it. Employees working for a licensed contractor don't.²⁰
• Where it doesn't apply. The county article applies only outside a city, town or village that licenses home improvement itself. The county's application warns that Yonkers "has additional licensing requirements."²⁰
• What it takes. A notarized application from the owner, proof of the business name, a liability certificate naming the Department of Consumer Protection as certificate holder and listing the work covered, a workers' comp and disability certificate (or the CE-200 exemption), photo ID for every owner, officer and salesperson, and a child support form for sole proprietors and partners.²⁰ No exam. The law leaves the insurance amount to the director, and the 2026 application doesn't print one, so ask before you buy the policy. The director may also require a bond of up to $50,000.²⁰
• Cost and time. $750 for two years since January 1, 2026 (it was $500), $50 extra if you renew less than 15 days before it expires. Processing "takes approximately sixty (60) business days," or 7 business days for an extra $100.^{20, 21}
• Vehicles. A $10 decal for each vehicle you use on the work. Any vehicle parked at a Westchester job site shows your name and address on both sides, readable from 50 feet.²⁰
• Paperwork. Your license number on "all advertising, stationery, proposals, change orders, and invoices" and in every contract. Contracts in writing, with dates, the work, the make and model of equipment, a three-day cancellation notice, and where the deposit sits.²⁰
• Supervision. Failing to "provide direct supervision over subcontractors or employees hired by licensee at job site" is a violation of the law.²⁰
• Gas and wiring. The license doesn't cover plumbing or electrical work, and "Plumbers and Electricians must obtain a trade license from Westchester County."^{20, 22}

The county asked town building departments to make sure "no permits are issued to unlicensed contractors."¹⁹ Expect the permit desk to ask for your license number.

Nassau and Suffolk County HVAC license (Long Island)

Nassau County

Nassau's home improvement license is the one the December 2025 court case turned on. The county's list of licensed work starts with "air conditioning & heating systems," and its definition of home improvement covers homes of up to three families and names "central heating or air conditioning systems."²³ Commercial-only contractors don't need it.²⁴

• Experience. "One owner/officer/principal must have at least 5 years of recent, relevant verifiable experience," shown with five years of W-2s, 1099s or another municipality's license.²⁴ Five years as a tech on someone's payroll counts, with the W-2s to show it.
• Insurance. Bodily injury $250,000/$500,000 and property damage $100,000, no deductibles, with the county as certificate holder. The certificate must describe your actual work: "the words 'General Contracting', 'Remodeling', 'Carpentry', and 'Home Improvement' will NOT be accepted." If you subcontract, the policy must allow it.²⁴ Workers' comp on a U-26.3 or C-105.2, or a CE-200.²⁴
• The rest. An EPA lead (RRP) certificate for at least one principal, a business location in New York State (a P.O. box doesn't count), a federal EIN, fingerprints (about $90), and a disclosure form for every principal and salesperson.²⁴
• Cost. $650 for two years plus a one-time $50 to the restitution fund. $110 late fee if you renew more than 15 days after it expires.²⁴
• Before it arrives. "A LICENSE MUST ACTUALLY BE IN THE POSSESSION OF THE LICENSEE BEFORE ANY WORK, ADVERTISING, OR SOLICITATION."²⁴ No work and no ads while you wait.
• On the job. A copy of the license at every job site and in each vehicle. Your license number on every contract and in display ads. The homeowner gets your insurance certificate and the names and license numbers of your subs, and every sub except plumbers and electricians needs its own Nassau license.^{25, 24}
• Oil service contracts. If you sell oil burner service, Nassau's Rule 15 sets what the contract must say: the annual price, the parts and labor covered, after-hours charges at your prevailing labor rate, and any cancellation penalty in bold above the signature line.²⁵
• Gas and wiring. "The towns, cities, and villages in Nassau County license plumbers and electricians."²⁶

Suffolk County

Suffolk's definition of home improvement contracting covers "any repair, remodeling, alteration, conversion, modernization, ... improvement or addition to residential property," and names "ductwork for heating, ventilation and air-conditioning systems." Residential property means one- and two-family houses. The list is open-ended ("includes but is not limited to"), so I'd hold the license for equipment installs as well as ducts.²⁷

• What it takes. A written test on the license rules for the individual applicant, insurance and workers' comp certificates on file before the license issues, and an establishment in New York State.²⁷ The county may require liability insurance "in the amount of $500,000 per occurrence combined single limit" and a surety bond of up to $100,000.²⁸
• Cost. $200 to apply and $200 a year. Half price if your net income from the business is $20,000 a year or less and you're not incorporated.²⁷
• Ads. "All advertising for home improvement contracting shall contain the number of the home improvement license."²⁷
• Service calls. Suffolk exempts "a contractor engaged in the field of home maintenance," which it limits to "the simple repair of existing facilities and systems."²⁷ A tune-up or a capacitor fits that, as I read it. A system replacement doesn't.
• Gas. Suffolk's plumbing field, licensed by the county, covers piping and "appliances and appurtenances" on "gas service systems."²⁹ The gas line is a plumber's. Ask the county whether it counts the gas furnace itself as plumbing.
• Towns on top. Southampton licenses home improvement itself, names "heating and air conditioning," and says an unlicensed contractor "shall not collect any fee" and has no standing to file a lien.³⁰ Check the town before your first East End job.

Buffalo, if you go upstate

Buffalo makes it unlawful to "install, erect, alter, repair, service, reset or replace any heating or process system" without a heating contractor license or a license holder's supervision. The license needs a $10,000 bond, two years of installation experience and an exam with no exemptions.³¹

What your license covers in New York, piece by piece

None of these licenses has classes, tonnage limits or a residential versus commercial split of the kind other states use. The NYC registration covers mechanical permits in any building. The DCWP and county licenses cover homes only, and commercial-only work needs neither.^{1, 8, 20, 24, 27} What decides who does each piece is the trade:

Sources: NYC trades,^{3, 11, 12, 13, 14} Westchester,^{20, 22} Nassau,²⁶ Suffolk.^{27, 29}

Federal and state rules every New York HVAC business meets

EPA Section 608

"Any person servicing, installing or disposing of stationary appliances (except the disposal of small appliances) must be a section 608 certified technician." The seller of refrigerant has to check that the buyer is, or employs, a certified technician, and an office manager can buy on the company account with a copy of the techs' cards.³⁴ So the supply house will want those cards on file before your first jug of R-410A or R-454B. Search for an NYC 608 certification and you'll find schools, but the card is federal and good anywhere.

A2L refrigerants (R-454B, R-32)

Three layers apply in New York. Federal: EPA's May 2026 rule, effective July 27, 2026, lets residential AC and heat pump equipment made or imported before January 1, 2025 "continue to be installed."³⁵ New York State: its own HFC rule, Part 494, bans new residential AC and heat pump systems using refrigerant with a 100-year global warming potential over 700 from January 1, 2026. DEC's October 2026 FAQ says nothing about following EPA's easing, and it warns that replacing components can make an existing system count as "new."³⁶ Ask DEC before you install leftover R-410A stock in New York. The same rule ends the sale of virgin R-410A in bulk containers in 2030.³⁶

New York City: the Mechanical Code has allowed A2L refrigerants since Local Law 77 of 2023, and in April 2026 DOB adopted the rule that goes with it. One- and two-family installs follow ASHRAE 15.2, anything over its charge limits or in a multifamily building follows ASHRAE 15, and the rule sets refrigerant detection, labeling and piping requirements.¹⁵ One more NYC catch: the permit exemption for refrigerating systems of "twenty-five tons or less in capacity" covers only systems "using a Group A1 refrigerant."⁵ R-410A is A1. R-32 and R-454B are A2L, as FDNY's training material lists them.¹⁶ So a new A2L split system doesn't fit that exemption, as I read it. Outside the city, towns enforce the state's Uniform Code, whose 2025 edition took effect on December 31, 2025.³³

EPA lead rules, when you cut into old walls

Running a line set or a new return through a home built before 1978 disturbs paint. Above 6 square feet per room inside, or 20 outside, your firm needs EPA certification and the work must be "directed by renovators certified" by EPA. Jobs in the same room within 30 days count as one.³⁷ The federal penalty is up to $49,772 per violation.³⁷ Nassau wants an RRP certificate for one principal before it licenses you, and DCWP wants the certificate or a signed statement that you don't need it.^{24, 10} In NYC rentals built before 1960, Local Law 1 lowers the trigger to 2 square feet; the general contractor article has those rules.

Helpers, techs and subs

New York has no HVAC journeyman or apprentice license, in the city or the three counties, and I found no helper-to-licensee ratio for HVAC work. A helper on your payroll needs no registration of their own for the HVAC work. The county licenses exempt employees working for wages, and so does DCWP's.^{20, 24, 27, 9} Three things do apply. Anyone touching refrigerant needs a 608 card.³⁴ In NYC, nobody on your crew may do gas or electrical work unless they're on a licensed master's payroll and under that master's supervision.^{11, 14} And a 1099 sub is a contractor: in Nassau they need their own license unless they're a plumber or electrician, DCWP says the same for NYC homes, and Westchester makes you supervise subs and employees on the job site.^{24, 10, 20}

Permits and inspections

In New York City

• How to file. Mechanical permits go through DOB NOW, with an NYC.ID account.⁴ A professional engineer or architect files the plans, and the permit issues to the registered contractor.²
• No permit needed. A packaged AC unit of up to 5 tons in an existing one- or two-family house, a packaged unit of up to 3 tons in any building, an A1-refrigerant system of 25 tons or less, and a one-floor voluntary AC or ventilation system that uses no lot-line openings, isn't in a public hall or stair, doesn't reduce required ventilation and doesn't penetrate a fire division, roof, floor or wall.⁵ The exemption doesn't cover the related electrical or plumbing connections, which the trades still file.⁵
• Like-for-like change-outs. A gas furnace or boiler swap is the master plumber's, often with no permit (above). An AC condenser or split system swap is yours: no permit if the new system is an A1 system under 25 tons, otherwise file. An oil boiler swap is the oil burner installer's.^{12, 5}
• No heat in January. Licensed trades may replace heating or hot water equipment in homes during the heating season before the permit, as emergency work, and file within two business days.²
• Inspection. DOB inspects "upon final completion" and checks that the equipment certificates of compliance "match the installed equipment model number, capacities," and that the special inspector filed the final report. New and altered heating systems are tested under the Mechanical Code.⁴ Keep the model and serial of everything you install.
• Homeowners. NYC has no homeowner exemption for gas or electrical work: those rules apply to "any person."^{11, 14}

In Westchester, Nassau and Suffolk

The county licenses don't touch permits. Both the Westchester and Nassau laws leave "a system of permits and inspections" to the city, town or village.^{20, 25} Each building department enforces the state Uniform Code, and each decides which change-outs need a permit, so call before your first job in a new town.³³

The gas utility

Con Edison (most of NYC and Westchester) says "All electric and gas work must be completed by licensed plumbers or electricians."¹⁷ National Grid (Brooklyn, Queens, Staten Island and Long Island) keeps "the sole right to disconnect, remove or reset gas services and/or meters, and to admit gas" to new or idle piping. On a residential new meter set, National Grid purges the piping and lights the appliances itself. When its warning tag shuts off a single appliance, "a licensed qualified contractor" may restore it after the repair, but a meter locked off goes back to National Grid. On a new installation, the master plumber gives National Grid an Operator Qualified Task 87 number.¹⁸

Can I take this job? A table for New York HVAC contractors

"Yes" means your registration or county license covers it. "Yes, with a permit" means a filing comes first. "Sub it out" means another licensed trade does that part, on its own license. The verdicts assume a one- or two-family house unless the row says otherwise.

What happens if you cross the line

Working without the license

• NYC homes without the DCWP license. A misdemeanor: up to six months in jail, a $1,000 fine, or both, per violation, plus civil penalties of up to $1,000 each and up to three times the owner's damages where it's willful. The City can seize a vehicle used for unlicensed work.⁴² DOB can also seize "vehicles and tools used in connection with unlicensed or unregistered activity."⁴⁴
• Westchester. A Class A misdemeanor, and civil penalties of up to $5,000 for a first violation, $10,000 for a second within five years and $15,000 after that. Vehicles and tools can be seized and impounded, and you can't get them back until you've applied for the license.²⁰
• Nassau. A Class A misdemeanor, with "each such violation" a separate offense, and penalties of up to $5,000 per violation. The county can seize the vehicle and its contents when it arrests an unlicensed contractor.²⁵
• Suffolk. A misdemeanor: up to $5,000 or a year in jail, each violation a separate offense, plus civil penalties of $750 and then $1,500.²⁸
• Buffalo. An unclassified misdemeanor: up to $1,000 or 60 days.³¹

Getting paid

This is the expensive part. In Nationwide HVAC Supply Corp. v. Mosby (December 2025), the installer put an HVAC system in a Nassau house, wasn't licensed by the county, and sued for the balance. The court held it "may not recover damages for breach of contract" and "has forfeited the right to foreclose the mechanic's lien," and rejected the argument that a licensed subcontractor did the install.⁴⁶ The Court of Appeals had already held, in a Manhattan renovation case, that a license obtained after the work doesn't help.⁴⁵ And when you sue a consumer over work that needs a license from New York City, Nassau, Suffolk, Westchester, Putnam or Rockland, your complaint must state your license name and number, or it can be dismissed.⁴⁷ Southampton goes further: an unlicensed contractor "shall not collect any fee, deposit, payment."³⁰

Trade work and permits

• Unlicensed plumbing work in NYC, gas included: a minimum civil penalty of $2,500 for a first violation and $5,000 for a second. Unlicensed electrical work: a minimum of $4,800.⁴³
• NYC permit violations: up to $500 for a lesser one, $1,000 to $10,000 for a major one, $2,500 to $25,000 for an immediately hazardous one, plus daily penalties.⁴³

Insurance

I found no New York rule that voids a policy for unlicensed work. The practical risk sits on the certificate: Nassau won't accept a policy that describes your work as "Home Improvement" or "General Contracting," and Westchester asks for the scope and exclusions.^{24, 20} If the policy doesn't name HVAC, ask your agent in writing whether it covers the work, and keep the reply. One HVAC owner on Reddit learned the order the hard way: "To get insurnace i need registered LLC in my state. So basically, they're looking for an established entity." (r/HVAC). Entity first, then the policy, then the license.

Your first 30 days: the New York HVAC license checklist

This is the whole list. The printable version has the same items with blanks for your registration and license numbers, policy and bond numbers, EPA 608 card numbers and renewal dates: make your own copy in Google Docs, download the Word version (.docx), or download the PDF. Pick a format, enter your email and I'll send the links.

The business

• ☐ Entity. LLC or corporation filed with the New York Department of State, or a business certificate from the County Clerk for a sole proprietor using a trade name. Get the federal EIN; Nassau won't process an application without one.^{6, 24}
• ☐ LLC publication. Within 120 days of forming an LLC, publish once a week for six weeks in the two newspapers the County Clerk designates, and file the certificate of publication.⁴⁰
• ☐ Sales tax. Apply for a Certificate of Authority at least 20 days before you start. Repairs and service calls are taxable. A new system installed for good is usually a capital improvement, untaxed once the customer gives you Form ST-124, which you keep.³⁹
• ☐ Workers' comp, disability and Paid Family Leave for your employees, or a CE-200 exemption if you have none. Every licensing office asks for one or the other.^{41, 6, 20, 24}
• ☐ General liability sized for the strictest place you work: $1 million for the NYC registration; $250,000/$500,000 and $100,000 in Nassau; up to $500,000 combined in Suffolk. Make sure the policy says HVAC.^{6, 24, 28}

New York City

• ☐ Registration current: DOB general contractor registration, renewed every three years ($240), with $25,000 operating capital and the insurance kept up. Look yourself up on DOB's license search.⁶
• ☐ Place of business question asked: does DOB want an NYC office for your registration?^{1, 7}
• ☐ DCWP home improvement license before you sign HVAC work in NYC homes: apply, pass the exam, $200 Trust Fund or $20,000 bond, $50 or $250 fee depending on the end date you pick.¹⁰
• ☐ Trades lined up and looked up: a master plumber (gas and gas appliances), a master electrician (circuits, controls) and, if you touch oil, an oil-burning equipment installer.^{11, 13, 14}
• ☐ An engineer or architect you can call for permitted installs, and DOB NOW and NYC.ID accounts.^{2, 4}

Westchester

• ☐ County home improvement license with HVAC ticked: notarized application, $750, liability certificate naming the Department of Consumer Protection, workers' comp and disability or CE-200. Allow about 60 business days, or pay $100 for 7. Westchester's page.²⁰
• ☐ Vehicle decals ($10 each) and your name and address on both sides of every work vehicle.²⁰
• ☐ Working in Yonkers, or a city, town or village with its own home improvement license? Ask for theirs.²⁰

Nassau

• ☐ County home improvement license: five years' experience for one principal, RRP certificate, insurance at $250,000/$500,000 and $100,000 naming HVAC, workers' comp, fingerprints, $650 plus the $50 restitution fee. No work or ads until it arrives. Nassau's page.²⁴
• ☐ License copy in every vehicle and at every job site.²⁵

Suffolk

• ☐ County home improvement license: written test, $200 plus $200 a year, insurance and workers' comp certificates.^{27, 28}
• ☐ Town licenses where you work, starting with Southampton on the East End.³⁰

Refrigerant, lead and gas

• ☐ EPA 608 cards for everyone who touches refrigerant, copies on file at the supply house.³⁴
• ☐ A2L: new installs on R-454B or R-32, to ASHRAE 15.2 in NYC homes. Check with DEC before installing any leftover R-410A system.^{15, 36}
• ☐ EPA lead-safe (RRP) firm certification and a certified renovator if you'll cut into pre-1978 walls.³⁷
• ☐ Gas utility: know who lights what. Con Edison works through licensed plumbers; National Grid lights appliances on new residential meter sets and controls locked meters.^{17, 18}

Your name and number on everything

• ☐ Trucks: NYC registration number and business information (DOB's instruction), Westchester decal plus name and address on both sides, Nassau license copy inside.^{1, 20, 25}
• ☐ Ads, website, quotes, change orders, invoices and contracts: the license number for each place you work. NYC, Westchester, Nassau and Suffolk each require it in ads; NYC and Westchester require it on contracts too.^{48, 20, 25, 27}
• ☐ Written contracts for home jobs over $500, with deposits in a New York escrow account within five business days or covered by a bond. The New York home improvement contract template has the required items.³⁸

Renewal

• ☐ Dates in the calendar: DOB registration (three years from issue), DCWP (February 28, 2027 for every current license), Westchester and Nassau (two years; renew at least 15 days early in Westchester), Suffolk (yearly fee).^{6, 10, 20, 24, 27}
• ☐ Changes reported: Westchester within 10 days of any change in owners, managers, name or address; NYC licensees within 30 days of an address change.^{20, 7}
• ☐ Continuing education: none required by the DOB registration or the three county licenses, as far as I found.

More for new HVAC contractors

• HVAC pricing guide: what to charge for a service call, your labor rate and the first jobs, with a free rate sheet.
• HVAC tune-up checklist: the visit in order, the target readings and what to charge, with a free report card.
• Opening a supply house account: what to bring, cash or credit, and how dealer programs work, with a free checklist.
• Quoting your first system replacement: the price, the scope and what the quote must include, with a free proposal template.
• Starting an HVAC business while still employed: side work, your boss's customers, non-competes and when to go.
• Register every install: maker deadlines, your labor warranty and what a callback costs, with a free close-out sheet.
• Your first slow season: the customer list and the one reminder that fills a calendar, with a free log.

Where Deepsel fits

Deepsel is the field service software I build, and it doesn't know New York licensing. It won't stop you quoting a gas line in Queens, track your DOB, DCWP or county license dates, or file in DOB NOW. What it does on the paperwork side: the shop-wide terms you write once are copied onto every new quote and your invoice footer onto every invoice, so your NYC, Westchester and Nassau license numbers reach the customer every time. Equipment records hold the type, brand, model, serial, year, filter size, tonnage, refrigerant and a nameplate photo, so the model number DOB's final inspection checks is on file, and so is everything you'll want at the next service call. Jobs and quotes take internal attachments (office and techs only) for a permit printout or a signed ST-124. Free covers 30 estimates and 30 invoices a month for your whole team, with scheduling and dispatch, quotes customers sign on screen, invoicing, card payments, and customer and equipment records; Pro is $29 a month with unlimited estimates and invoices (pricing).

Frequently asked questions

Do you need an HVAC license in New York?

Not from the state. I found no New York State HVAC license, and the state's building codes division says licensing of contractors isn't something it handles. The license comes from where the job is. New York City splits HVAC work between a DOB general contractor registration (for mechanical permits), a DCWP home improvement license (for homes), a master plumber (gas), an oil-burning equipment installer (oil) and a master electrician (wiring). Westchester, Nassau and Suffolk counties license HVAC work through their home improvement licenses, and Buffalo has a heating contractor license.

What license do I need to do HVAC work in NYC?

For the business: a DOB general contractor registration, because DOB issues mechanical permits only to a registered general contractor, plus a DCWP Home Improvement Contractor license for work in one- to four-family homes and apartments once a job reaches $200. For the trades inside the job: a DOB-licensed master plumber for gas piping and gas appliance replacement, an oil-burning equipment installer for oil burners and oil boilers, and a master electrician for the circuit and disconnect. Anyone who handles refrigerant needs an EPA Section 608 card.

Does Westchester County require an HVAC license?

Yes, since the first week of July 2025. It's the county's home improvement license, issued by the Department of Consumer Protection, with HVAC now on the list of home improvement work. It costs $750 for two years, needs liability insurance and workers' comp (or the CE-200 exemption) on file, and comes with a decal for each work vehicle. There's no exam. Where a city, town or village licenses home improvement itself, the county license doesn't apply there, and Yonkers has additional requirements of its own. Gas piping still needs a Westchester-licensed plumber.

Do I need a license for HVAC work in Nassau or Suffolk County?

Yes, a county home improvement license for residential work. Nassau's list names air conditioning and heating systems; the license is $650 for two years plus $50 to a restitution fund, and needs five years of experience from one owner or officer and liability insurance of at least $250,000/$500,000 bodily injury and $100,000 property damage. Suffolk's definition names HVAC ductwork; the license is $200 to apply and $200 a year, after a written test. Neither covers gas piping, which goes to a licensed plumber, and some East End towns such as Southampton add a town license.

Is there an HVAC certification in New York?

The one every HVAC business needs is federal: EPA Section 608 certification for anyone who services, installs or disposes of equipment with refrigerant, and supply houses must check it before they sell you refrigerant. New York State has no HVAC certification of its own. School certificates and manufacturer training are useful, but no New York licensing office I read asks for them.

What is the NYC refrigeration license?

Usually people mean FDNY's Certificate of Qualification for a Refrigerating System Operating Engineer (Q-01). It isn't a contractor license. Any refrigerating system that needs an FDNY permit must run under the supervision of a Q-01 holder, and the certificate is tied to the premises. Installing a residential split system doesn't need one, and New York City has no refrigeration contractor license.

Can an HVAC contractor run a gas line in New York?

Not without a plumbing license. In New York City, gas piping is plumbing work, and only a licensed master plumber or people working under one (with DOB's gas work qualification) may do it. In Suffolk, the plumbing field includes gas service systems; Westchester licenses plumbers at the county level; and in Nassau the towns, cities and villages license plumbers. Unlicensed plumbing work in NYC carries a minimum civil penalty of $2,500 for a first violation.

Does my NYC general contractor registration work on Long Island or in Westchester?

No. It's a New York City Department of Buildings registration, and it lets you hold mechanical permits in the five boroughs. Westchester, Nassau and Suffolk each require their own license for HVAC work on homes. In December 2025 an appeals court held that an HVAC installer without a Nassau license couldn't sue the homeowner or foreclose its mechanic's lien, even though a licensed subcontractor did the installation.

Sources

1. NYC Department of Buildings, "Registrant Project Requirements: Mechanical Work & Site Requirements" ("Permits for mechanical systems work are only issued to the Registered General Contractor (GC)"; HIC license required for one- to four-family homes and apartment units "in addition to the GC license"; NYC place of business "as per §28-401.18"; license number and business information on trucks, business cards and advertisements). nyc.gov, read November 3, 2026.
2. NYC Department of Buildings, "Project Requirements Owner: Mechanical" (service equipment exempt under 1 RCNY 101-14; emergency replacement of heating or hot water equipment in residential occupancies during the heating season, filed within two business days; "The owner must hire a Registered Design Professional to submit permit application plans to the Department prior to work being performed by a General Contractor"; ordinary plumbing work by a licensed master plumber). nyc.gov, read November 3, 2026.
3. NYC Department of Buildings, "Mechanical: Allowable Work Without A Registered Design Professional" (mechanical work including "piping, fuel-burning equipment, ductwork, air-conditioning equipment, electric wiring" by designated skilled trades; limited gas boiler work by a licensed master plumber; limited oil-burning boiler work by a licensed oil burner installer; "boiler line voltage work and controls" by a licensed electrician). nyc.gov, read November 3, 2026. The page's dollar and BTU limits are older than the current code in source 12.
4. NYC Department of Buildings, "Mechanical Work & Inspections" (final inspection "upon final completion"; equipment certificates of compliance checked against model number and capacities; special inspection agency final report TR1; heating systems tested under MC 1011), nyc.gov; NYC311, "Heating or Ventilation System Permit" (DOB NOW; NYC.ID required), portal.311.nyc.gov. Both read November 3, 2026.
5. 1 RCNY § 101-14, Categories of Work That May or May Not Require a Permit (amended effective June 10, 2026): (c) exemptions don't remove filings for "electrical connections, or plumbing connections"; Table 1 item 5, packaged AC up to 5 tons in existing one- and two-family dwellings; Table 2 section II items 1 (one-floor voluntary AC and ventilation systems, with conditions), 2 (packaged AC up to 3 tons) and 6 ("Refrigerating systems twenty-five tons or less in capacity and using a Group A1 refrigerant"). codelibrary.amlegal.com, read November 3, 2026.
6. NYC Administrative Code Article 418: § 28-418.1 (registration required), § 28-418.2 (title "registered general contractor"), § 28-418.3 item 9 (officer, principal or director responsible for compliance), § 28-418.3.1 (operating capital over $25,000), codelibrary.amlegal.com; DOB, "General Contractor Registration" ($300, $240 renewal, three years), nyc.gov; DOB registration guidelines, Rev. 02/26 ($25,000 bank balances, $1 million liability, workers' comp and disability certificates, LIC50 for applicants living outside the five boroughs, business certificate or DOS filings), nyc.gov (PDF); DOB, "Contractors" (Insurance Tracking Number, GC registration or Safety Registration Number for other alteration work), nyc.gov. All read November 3, 2026.
7. NYC Administrative Code § 28-401.18 (licensee's business must have "an established place dedicated to the licensee's business with an address within the city of New York"; no P.O. box or virtual office) and § 28-401.18.1 (address changes within 30 days). codelibrary.amlegal.com, read November 3, 2026.
8. NYC Administrative Code §§ 20-386 to 20-388: home improvement includes "the installation of central heating or air conditioning systems" "without regard to the extent of affixation"; building of no more than four dwelling units; tenant, co-op and condo contracts; § 20-387 license required, no other license or authority suffices; § 20-388 biennial fee of $200. codelibrary.amlegal.com, read November 3, 2026.
9. NYC Administrative Code § 20-397 (exemptions: employees for wages; licensed trades "required by state or city law to attain standards of competency" acting exclusively within scope; jobs where "the aggregate contract price for all labor materials and other items is less than two hundred dollars," not split or part of a larger operation) and § 20-389 (license not assignable). codelibrary.amlegal.com, codelibrary.amlegal.com, read November 3, 2026.
10. NYC Department of Consumer and Worker Protection, "Home Improvement Contractor License Application Checklist" (exam of 30 questions, 21 to pass; fingerprints; $200 Trust Fund or $20,000 surety bond; workers' comp; EPA certification or affirmation; sales tax ID; $50 or $250 prorated fees, licenses expiring February 28 of odd years), nyc.gov; DCWP, "Inspection Checklist: Home Improvement Contractors," updated 06/2026 ("All subcontractors you use must have a DCWP Home Improvement Contractor license"), nyc.gov (PDF). Both read November 3, 2026.
11. NYC Administrative Code § 28-401.3 (plumbing work includes gas piping and "any piping system referred to in the New York city plumbing code"; direct and continuing supervision; direct employ), codelibrary.amlegal.com; § 28-408.1 (plumbing work only by or under a licensed master plumber), codelibrary.amlegal.com; § 28-423.1 (gas work only by a master plumber, or under one with a full or limited gas work qualification), codelibrary.amlegal.com. All read November 3, 2026.
12. NYC Administrative Code § 28-101.5, definitions of "limited plumbing alterations" (category 2 includes in-kind replacement of gas-fired appliances of 3 million Btu/h or less) and "limited oil-burning appliance alterations" (replacement of oil burners and appliances up to 3 million Btu/h; tanks of 330 gallons or less), codelibrary.amlegal.com; § 28-105.4.4 item 5 (ordinary plumbing work: replacing a gas water heater, gas furnace or gas-fired boiler of 350,000 BTU or less in buildings of five families or fewer, shutoff valve not moved, by a licensed plumber with monthly reports), codelibrary.amlegal.com. Both read November 3, 2026.
13. NYC Administrative Code § 28-412.1 ("It shall be unlawful to install oil-burning equipment in the city unless such work is performed by or under the direct and continuing supervision of a person licensed as an oil-burning equipment installer") and § 28-412.2 (equipment includes "burners, boilers and generators"). codelibrary.amlegal.com, read November 3, 2026.
14. NYC Administrative Code § 28-429.1 (electrical work only by or under a licensed master electrician), codelibrary.amlegal.com; § 28-105.4.7 (low-voltage work under 50 volts without a permit; exception 1.4, "A point of connection to or interfacing with a control circuit that activates light, heat, or power circuits," reserved to master or special electricians), codelibrary.amlegal.com. Both read November 3, 2026.
15. NYC Department of Buildings, Notice of Adoption of Rule on refrigerants, dated April 7, 2026 (Local Law 77 of 2023 amended the Mechanical Code for A2L refrigerants; new 1 RCNY §§ 7011-01, 7015-02, 7015-03 and 7015-04; ASHRAE 15.2 for one- and two-family dwellings, ASHRAE 15 above its limits and for R-1 and R-2 occupancies; detection, signage and piping requirements), a856-cityrecord.nyc.gov (PDF); 1 RCNY § 7011-01, nyc.gov (PDF). Both read November 3, 2026.
16. FDNY, "Certificates of Qualification" ("Any refrigerating system requiring an FDNY permit must be under supervision of a Certificate of Qualification (Q-01 Refrigerating System Operating Engineer) holder while the system is in operation"; premises related), nyc.gov; FDNY, "A2L Refrigerant and Compliance Requirement" study material (A2L examples include R-32 and R-454B, replacing older A1 refrigerants), nyc.gov (PDF). Both read November 3, 2026.
17. Con Edison, Building and Remodeling Project Center FAQ ("All electric and gas work must be completed by licensed plumbers or electricians"). coned.com, read November 3, 2026.
18. National Grid, "Bluebook: Specifications and Requirements for Gas Installations, New York City and Long Island," Revision 13, July 2025: 3.11 (sole right to admit gas), 3.12 (warning tags; restoration by "a licensed qualified contractor"), 4.1.3 (Operator Qualified Task 87 number from the licensed master plumber), 7.14.3 (National Grid purges and lights appliances on residential new meter sets). nationalgridus.com (PDF), read November 3, 2026.
19. Westchester County, "Westchester County Issues Reminder on New HVAC and Power Washer Licensing Rules," July 28, 2025. westchestercountyny.gov, read November 3, 2026.
20. Westchester County Department of Consumer Protection, Home Improvement License application packet (dated February 23, 2026), with the Laws of Westchester County, Chapter 863, Article XVI: § 863.312 (definitions, including "r. HVAC"; dwellings of not more than three units; employees excluded), § 863.313 (license required; vehicle decals, $10), § 863.315 ($750 for two years; $50 late renewal), § 863.318 (not assignable), § 863.319 (license number on advertising, stationery, proposals, change orders, invoices and contracts; changes within 10 days; direct supervision of subcontractors and employees), § 863.320 (Class A misdemeanor), § 863.321 (other licenses; municipal permits; areas licensing on their own), § 863.324 (plumbing and electrical work excluded; insurance amount set by the director; bond up to $50,000), § 863.326 (name and address on both sides of vehicles), § 863.328 (seizure of vehicles and tools), § 863.329 (contract contents), and § 277.171 (civil penalties of $5,000, $10,000 and $15,000); application checklist (insurance and workers' comp certificates naming the department; about 60 business days, or 7 for $100; Yonkers). consumer.westchestercountyny.gov (PDF), read November 3, 2026.
21. Westchester County, Local Law 2025-496, "Adjust Certain Fees and Fines" (home improvement license from $500 to $750; effective January 1, 2026). westchestercountyny.legistar.com, read November 3, 2026.
22. Westchester County Department of Consumer Protection, "Plumbing and Electrical Licenses" ("Plumbers and Electricians must obtain a trade license from Westchester County in order to work in the county"). consumer.westchestercountyny.gov, read November 3, 2026.
23. Nassau County Department of Consumer Affairs, "Who Must Be Licensed?" (home improvement definition naming "central heating or air conditioning systems"; homes of not more than three families; list starting with "air conditioning & heating systems"). nassaucountyny.gov, read November 3, 2026.
24. Nassau County Department of Consumer Affairs, "General Instructions for a Home Improvement License" (8-2024: license in possession before work or advertising; New York location; EIN; RRP certificate; five years' experience; insurance; workers' comp or CE-200; fingerprints about $90; subcontractors licensed except plumbers and electricians; $650 and $50 restitution), nassaucountyny.gov (PDF); "Insurance Requirements" (bodily injury $250,000/$500,000, property damage $100,000, no deductibles, specific description of work), nassaucountyny.gov; "FAQs: Obtaining a Home Improvement License" (commercial-only contractors exempt; employees exempt; $110 late fee), nassaucountyny.gov. All read November 3, 2026.
25. Nassau County Administrative Code, Title D-1, Article 1 (Local Law 6-1970 with amendments): § 21-11.2 (license required), § 21-11.3 (other licenses; municipal permits), § 21-11.15 (Class A misdemeanor; penalties up to $5,000 per violation), vehicle seizure, and the department's rules: Rule 11 (license copy at job sites and in each vehicle), Rule 14 (subcontractor names and license numbers), Rule 15 (home fuel oil and oil burner service contracts), Rule 17 (license number on contracts and display advertising; license not to be used by another). nassaucountyny.gov (PDF), read November 3, 2026.
26. Nassau County Department of Consumer Affairs, "Consumer Affairs Jurisdiction" ("The towns, cities, and villages in Nassau County license plumbers and electricians"). nassaucountyny.gov, read November 3, 2026.
27. Suffolk County Code, Chapter 563, Article II, Home Improvement Contractors: § 563-16 (definitions, including "ductwork for heating, ventilation and air-conditioning systems," home maintenance, residential property as one- and two-family houses), § 563-17 (license required; written test; insurance and workers' comp certificates; license number in all advertising), § 563-19 ($200 application, $200 a year), § 563-23 (exemptions, including employees and home maintenance), § 563-24 (half fee). ecode360.com, read November 3, 2026.
28. Suffolk County Code, Chapter 563, Article I: § 563-9 (civil penalties of $750 and $1,500), § 563-11A(4) (surety bond up to $100,000 and/or liability insurance of $500,000 per occurrence combined single limit), § 563-12 (unlicensed business a misdemeanor, up to $5,000 or one year). ecode360.com, read November 3, 2026.
29. Suffolk County Code, Chapter 563, Article XI, § 563-126 ("plumbing field" includes piping, fixtures, "appliances and appurtenances" in connection with gas service systems). ecode360.com, read November 3, 2026.
30. Town of Southampton Code, Chapter 143, Article I: definition of home improvement naming "heating and air conditioning"; § 143-2 (license required; unlicensed contractor "shall not collect any fee, deposit, payment"; no standing to record a lien), amended by L.L. 9-2024. ecode360.com, read November 3, 2026.
31. City of Buffalo Code, Chapter 238, Heating: § 238-7 (license required to "install, erect, alter, repair, service, reset or replace any heating or process system"; unclassified misdemeanor, up to $1,000 or 60 days), § 238-9 ($10,000 bond), qualifications (two years' experience) and § 238-12 (no exemptions from examination). ecode360.com, read November 3, 2026.
32. New York State Attorney General, "Contractors and home maintenance" ("Home-improvement contractors must be licensed in New York City, Suffolk, Nassau, Westchester, Putnam, and Rockland counties, and the City of Buffalo"). ag.ny.gov, read November 3, 2026.
33. New York Department of State, Division of Building Standards and Codes, FAQ ("Issues regarding local laws, zoning, and licensing of contractors or electricians are not handled by this Division"), dos.ny.gov; "Adoption of the 2025 Uniform Fire Prevention and Building Code" (effective December 31, 2025), dos.ny.gov (PDF). Both read November 3, 2026.
34. US EPA, "Questions and Answers about the Refrigerant Sales Restriction" ("Any person servicing, installing or disposing of stationary appliances (except the disposal of small appliances) must be a section 608 certified technician"; seller verifies the buyer is or employs a certified technician). epa.gov, read November 3, 2026.
35. US EPA, "Phasedown of Hydrofluorocarbons: Reconsideration of Certain Regulatory Requirements Promulgated Under the Technology Transitions Provisions of the American Innovation and Manufacturing Act of 2020," final rule, 2026-10387, published May 26, 2026, effective July 27, 2026 (pre-2025 residential and light commercial AC and heat pump inventory may continue to be installed). federalregister.gov, read November 3, 2026.
36. New York State Department of Environmental Conservation, "Frequently Asked Questions: Part 494," updated October 2026 (residential AC and heat pumps with GWP100 over 700 prohibited from January 1, 2026; replacing components can make a system "new"; virgin bulk R-410A sales end in 2030). dec.ny.gov (PDF), read November 3, 2026.
37. EPA Renovation, Repair and Painting rule, 40 CFR 745.81 and 745.83 (firm certification; renovations "directed by renovators certified"; 6 square feet per room inside, 20 outside; same room within 30 days is one job), ecfr.gov; 40 CFR 19.4, Table 1 ($49,772 per violation under 15 U.S.C. 2615(a)(1)), ecfr.gov. Both read November 3, 2026.
38. New York General Business Law §§ 770 and 771 (home improvement contracts over $500 in writing, with required contents), nysenate.gov; Lien Law § 71-a(4) (payments before substantial completion into a New York escrow account within five business days, or a bond), nysenate.gov. Both read November 3, 2026.
39. New York State Department of Taxation and Finance, TB-ST-175 (apply for a Certificate of Authority at least 20 days before you begin), tax.ny.gov; TB-ST-129 (repair, maintenance and installation services are taxable), tax.ny.gov; TB-ST-104 (capital improvements; Form ST-124), tax.ny.gov. All read November 3, 2026.
40. New York Limited Liability Company Law § 206 (publication within 120 days, once a week for six weeks in two newspapers designated by the county clerk). nysenate.gov, read November 3, 2026.
41. New York State Workers' Compensation Board, "Information for Employers/Businesses" (employers with employees in New York may be required to provide workers' compensation, disability benefits and Paid Family Leave coverage). wcb.ny.gov, read November 3, 2026.
42. NYC Administrative Code § 20-401 (misdemeanor, up to six months and $1,000 per violation; civil penalty up to $1,000; up to three times damages) and § 20-401.1 (vehicle seizure). codelibrary.amlegal.com, read November 3, 2026.
43. NYC Administrative Code § 28-202.1, civil penalties (lesser up to $500; major $1,000 to $10,000; immediately hazardous $2,500 to $25,000 plus daily penalties; exception 4, minimum $2,500 then $5,000 for violating § 28-408.1; item 12, minimum $4,800 for unlicensed electrical work). codelibrary.amlegal.com, read November 3, 2026.
44. NYC Administrative Code § 28-419.1 ("The vehicles and tools used in connection with unlicensed or unregistered activity at any work site shall be subject to seizure and forfeiture"). codelibrary.amlegal.com, read November 3, 2026.
45. B & F Bldg. Corp. v Liebig, 76 NY2d 689 (1990) (unlicensed contractor on a Manhattan co-op renovation; after-acquired license doesn't validate the contract). law.cornell.edu, read November 3, 2026.
46. Nationwide HVAC Supply Corp. v Mosby, 2025 NY Slip Op 06712 (2d Dept, December 2025) (HVAC system installed at a Nassau County home; no Nassau license under Administrative Code § 21-11.2; no recovery for breach of contract and the mechanic's lien forfeited; a licensed subcontractor doing the installation doesn't change that). courtlistener.com, read November 3, 2026.
47. New York CPLR 3015(e) (claims against a consumer by a business licensed by NYC's consumer affairs department, Suffolk, Rockland, Putnam, Westchester or Nassau must plead the license name and number). nysenate.gov, read November 3, 2026.
48. 6 RCNY § 2-221(a)(1) (contract states the contractor's license number) and § 2-222(a) ("All advertising and sales literature must contain the license number of the contractor"). codelibrary.amlegal.com, read November 3, 2026.