The New York State capital improvement tax exemption lets you avoid paying sales tax on qualifying construction and renovation work performed on your real property. On a big project, that’s real money: combined state and local rates run as high as 8.875%, so the exemption can knock several thousand dollars off a new roof, an addition, or a full kitchen remodel. To claim it, the work has to meet a three-part test under NY Tax Law § 1101(b)(9), and you have to give your contractor a signed Form ST-124 within 90 days of the sale.1New York State Senate. New York Tax Law 1101 – Definitions
The Three-Part Test
Under NY Tax Law § 1101(b)(9), an addition or alteration to real property is a capital improvement only if all three of these are true:
- It substantially adds to the property’s value or appreciably prolongs its useful life. Only one of those needs to be true.
- It becomes part of the real property, or is permanently affixed so that removing it would cause material damage to the property or the item itself.
- It is intended to remain as a permanent installation.
The value-or-life prong is forgiving. The permanence and intent prongs are strict. A unit you can unplug and roll out fails the second test regardless of how much value it adds. And an installation your lease requires you to rip out at the end of the term fails the third, even if it’s bolted down today.1New York State Senate. New York Tax Law 1101 – Definitions
Commercial tenants get burned on that intent prong more than anyone. The Department of Taxation and Finance uses the example of a hair salon installing sinks and plumbing. Installing a sink normally qualifies. But because the salon’s lease required restoring the space to its original condition, the work was taxable.2New York State Department of Taxation and Finance. Tax Bulletin ST-104 – Capital Improvements
What Qualifies and What Doesn’t
The pattern is consistent across the Department’s guidance: installing something new that becomes a permanent part of the property qualifies; fixing something already there does not.
Projects that qualify include building a deck, installing a hot water heater, installing kitchen cabinets, putting on a new roof, installing a complete new central HVAC system, adding a room, and building a new retaining wall. A full kitchen remodel with new built-in cabinets, countertops, and permanently installed appliances qualifies too. Freestanding appliances like a refrigerator that plugs into an outlet do not.2New York State Department of Taxation and Finance. Tax Bulletin ST-104 – Capital Improvements
Repairs and maintenance are taxable. Repairing a broken step, replacing a thermostat on a water heater, painting existing cabinets, fixing a leaky faucet, patching a section of roof — all subject to standard sales tax.
Mixed projects are where invoices get messy. If a contractor replaces a broken section of plumbing and also installs a brand-new water heater, the water heater installation may qualify while the pipe repair stays taxable. Ask for the charges to be separated on the invoice rather than lumped together.
Mobile Homes
The statute says a mobile home does not constitute a capital improvement to real property regardless of how it is installed. Even a mobile home permanently affixed to a foundation falls outside the exemption.1New York State Senate. New York Tax Law 1101 – Definitions
The Floor Covering Trap
Carpet, carpet padding, linoleum, vinyl roll flooring, and vinyl tile qualify as capital improvements in only one narrow situation: when installed as the initial finished floor covering in new construction, a new addition, or a total reconstruction of existing construction.1New York State Senate. New York Tax Law 1101 – Definitions
Replacing old carpet with new carpet in an existing room is not a capital improvement, even though the new carpet is permanently installed. Same story for swapping the linoleum in your kitchen. If a contractor tells you new flooring in an existing room is tax-exempt, push back unless you’re taking the space down to the studs.
How the Exemption Actually Lowers Your Bill
The exemption does not make the whole project tax-free. When a contractor performs a capital improvement, they do not charge you sales tax on the total project price. But the materials the contractor buys for the job are still fully taxable. The contractor pays sales tax to the supplier on lumber, fixtures, and wiring, then builds that cost into the price they charge you.2New York State Department of Taxation and Finance. Tax Bulletin ST-104 – Capital Improvements
If you buy the materials yourself and hire someone to install them, you pay sales tax on the materials at the register, but the labor charge for a qualifying capital improvement is still exempt. Either way, materials get taxed once. What the exemption really eliminates is sales tax on labor and on the contractor’s overall charge — which on a large project is where most of the savings live.
Filing Form ST-124
To claim the exemption, you complete and sign Form ST-124, the Certificate of Capital Improvement, and deliver it to your contractor. Both customer and contractor sign it, and the contractor keeps the completed original. The form is on the Department of Taxation and Finance website.3New York State Department of Taxation and Finance. New York State and Local Sales and Use Tax Certificate of Capital Improvement
The form asks for:
- Customer name and mailing address
- Contractor name and mailing address
- The street address where the work is being performed
- A specific description of the work
Write the description like it matters, because it does. “Installation of 30-year architectural shingle roof on 2,000 sq. ft. ranch home” is the right level of detail. “Construction work” is not. Vague descriptions and missing fields cause problems during an audit, because the Department needs enough information to see that the job actually met the legal definition.3New York State Department of Taxation and Finance. New York State and Local Sales and Use Tax Certificate of Capital Improvement
The 90-Day Deadline
You have to deliver the completed ST-124 to the contractor within 90 days of the date of the sale. Better to hand it over at the time of the transaction. Miss the 90-day window and the contractor should have collected sales tax on the job; unwinding that after the fact is a headache for both sides.4New York State Department of Taxation and Finance. Exemption Certificates for Sales Tax
Keep your own copy. The IRS recommends holding onto records tied to property improvements until the statute of limitations closes for the year you sell. Because capital improvements raise your cost basis and reduce your taxable gain when you sell, hanging onto receipts, invoices, and your copy of the ST-124 for as long as you own the property, and at least three years after you file the return for the year of sale, is the safe move.5Internal Revenue Service. How Long Should I Keep Records
What Happens If the Work Doesn’t Really Qualify
If sales tax should have been collected and wasn’t, New York imposes a penalty of 10% of the tax due for the first month of the failure, plus 1% for each additional month, up to a maximum of 30%. Interest runs on the unpaid tax. If a failure to file continues past 60 days, the minimum penalty is the lesser of $100 or 100% of the tax shown on the return. For registered vendors, the minimum penalty for failure to file is never less than $50. Fraud carries a penalty of two times the tax due, plus interest.6New York State Senate. New York Tax Law 1145 – Penalties and Interest
For homeowners, the practical risk of misclassifying a repair as a capital improvement is that the contractor comes back seeking the sales tax after an audit, or the Department pursues the tax directly. A properly completed ST-124 protects a contractor who accepts it in good faith. A sloppy one does not.
The Cost Basis Benefit at Sale
The sales tax break is the immediate savings, but capital improvements do a second job on your federal return. Every dollar spent on a qualifying improvement gets added to your property’s cost basis, which reduces your taxable gain when you sell. The IRS requires taxpayers to capitalize the cost of improvements to tangible property rather than deducting them as current expenses, and the line between a deductible repair and a capitalizable improvement follows a facts-and-circumstances analysis under Section 263(a) of the Internal Revenue Code.7Internal Revenue Service. Tangible Property Final Regulations
That’s another reason to hold onto the ST-124 along with your receipts. The same paperwork that establishes the sales tax exemption today documents the basis increase you’ll claim years from now.
Watch for a Property Tax Reassessment
One consequence of a capital improvement catches homeowners off guard: the building permit you pull for the work can flag your property for reassessment. Room additions, finished basements, and new garages are the most likely triggers, but even a permitted deck can put you on the assessor’s radar. Reassessment frequency and practice vary by municipality across New York.
The sales tax savings are immediate and concrete. Higher property taxes, if they come, roll in year after year. That doesn’t mean skipping the improvement. It means running the full number before you sign the contract, not just the sales tax line.