Many home renovations qualify as capital improvements which are exempt from sales tax. Building materials purchased for capital improvement work are taxable (whether purchased by a contractor, subcontractor, or homeowner), and a contractor purchasing building materials on behalf of a homeowner is permitted to mark up their materials cost to the homeowner (including the cost of sales tax). However, homeowners may not be charged sales tax as a percentage of combined labor and materials costs for capital improvement work performed by a contractor.
If you ever see itemized sales tax on a receipt or invoice from a contractor for capital improvement work, you can likely claim this back from the New York Tax Department.

Sales tax savings calculated as a percentage of capital improvement expenditure.
Claimed by removing sales tax from capital improvement invoices (pre-purchase) or as a refund from the New York State Tax Department (post-purchase). More information on refunds available here.
How to Claim
Supply your contractor with Form ST-124 and use Form AU-11 to apply for a refund. Form AU-11 needs to be filed with a paper form submitted by mail.
For assistance completing your refund, you can contact savings@castlepay.co or schedule a free consultation here.
Required Information
First, make sure that the work being completed qualifies as a capital improvement (as opposed to repair and maintenance). To qualify as a capital improvement, the work must:
- Substantially add to the value of your property, or appreciably prolong the life of your property;
- Become part of the property / become permanently affixed to the property such that removal would cause material damage to your property or the improvement being installed; and
- Be intended to become a permanent installation.
Second, you will need documentation of the capital improvement work done and documentation that you were improperly charged sales tax.
Timeline
You should aim to supply form ST-124 to your contractor before you pay for the capital improvement work. Form AU-11 can be submitted after the work is completed. You must submit Form AU-11 within three years from the date the tax was due to the Tax Department, or two years from the date you paid the tax, whichever is later.