Certificate of Capital Improvement (Form ST-124)

The Certificate of Capital Improvement (Form ST-124) is a New York State tax form that a property owner gives to a contractor to certify that the work being performed qualifies as a capital improvement—meaning the contractor does not charge sales tax on the job.

To be valid, the signed ST-124 must confirm that the work:

1. Adds value to the property

2. Becomes a permanent part of the real estate

3. Is intended to remain for at least one year

Once the homeowner provides a completed Form ST-124, the contractor must keep it in their records as proof the project was tax-exempt. If the form is missing, incomplete, or inaccurate, the contractor can be held liable for the uncollected sales tax.