N.Y. Comp. Codes R. & Regs. tit. 20 § 261.4
Tax Law, § 5(b) of § 1340(c); Codes and Ordinances of the City of Yonkers, § 92-102(b)
Where a short taxable period for Federal income tax purposes results from a change in a nonresident taxpayer's accounting period, such nonresident taxpayer must file a City of Yonkers earnings tax return for such short taxable period if such taxpayer has any wages earned, or net earnings from self-employment derived from, within the City of Yonkers during such short taxable period (see section 263.6 of this Title). Such nonresident taxpayer's earnings from wages and net earnings from self-employment must be computed on the basis of the period for which the City of Yonkers earnings tax return is made, and in accordance with the rules applicable to the determination of wages and net earnings from self-employment from City of Yonkers sources. The exclusion allowed by section 2(b) of the Model Local Law contained in section 1340(c) of the Tax Law, and section 92-99(b) of the Codes and Ordinances of the City of Yonkers, must be prorated according to the number of months covered by the short-period City of Yonkers earnings tax return.
Example:
A nonresident individual has been filing Federal and City of Yonkers earnings tax returns on the basis of a calendar year. Such individual changes to a fiscal-year basis ending June 30th and files a Federal and City of Yonkers earnings tax return for the short taxable period January 1st to June 30th. During this short period, such individual derived net earnings from self-employment from City of Yonkers sources totaling $15,000. Such individual's City of Yonkers taxable net earnings is determined as follows:
| Net earnings | $15,000 |
| Allowable exclusion | |
| (6/12 × $2,000) | $ 1,000 |
| City of Yonkers taxable | |
| net earnings | $14,000 |
N.Y. Comp. Codes R. & Regs. Tit. 20 § 261.4