New York Consolidated Laws, Tax Law - TAX § 3004-a. Disclosure of overpayment to taxpayer

(a) The department shall disclose to a taxpayer all instances of overpayment of tax by such taxpayer discovered by the department during the course of an audit, assessment, collection or enforcement proceeding.

(b) The time within which a taxpayer may apply for a refund or claim a credit for an overpayment of tax disclosed pursuant to this section shall be one hundred twenty days from the date that notice of disclosure is given to such taxpayer by the department.  Failure to apply for a refund or credit within the one hundred twenty days shall result in the loss of the right to apply for a refund or credit.  Provided, that this subdivision shall not reduce the time within which a taxpayer may claim a credit or refund of an overpayment of tax pursuant to any other provision of this chapter or any other applicable law.

(c) Nothing in this section shall be construed as requiring or permitting the giving of notice or the payment of a refund or granting of a credit with respect to a period which, at the time such overpayment is discovered by the department, is not open for assessment or refund by virtue of any period of limitations provided for in any tax.