N.Y. Comp. Codes R. & Regs. tit. 9, § 1727-2.5
(2) The income affidavit should be carefully reviewed. If the affidavit reflects a change in household composition from the prior year's affidavit, documentation should be requested by the housing company. The division will refer income reported by residents who provide social security numbers to the New York State Department of Taxation and Finance for verification. However, income documentation by the housing company is required in the following circumstances: If additional information or documentation is needed, a written request to that effect should be forwarded to tenant or cooperator and a copy of such request attached to “Occupant's Annual Affidavit of Family Income” form. The date on which information should be returned must be shown on notice and should normally be from 7 to 10 days from the date of the notice.
(ii) if a resident 18 years of age or older does not provide a social security number or claims not to have filed a New York State income tax return.
(b) Interim changes in rent.
Interim changes in rent to reduce or remove surcharges should be made, if required, only in the following circumstances:
(a) Annual income reexamination procedure.