26 C.F.R. § 31.3402(g)-2 Wages paid for payroll period of more than one year.
Title 26 - Internal Revenue
If wages are paid to an employee for a payroll period of more than one year, for the purpose of determining the amount of tax required to be deducted and withheld in respect of such wages— (a) Under the percentage method, the amount of the tax shall be determined as if such payroll period constituted an annual payroll period, and (b) Under the wage bracket method, the amount of the tax shall be determined as if such payroll period constituted a miscellaneous payroll period of 365 days.
Title 26: Internal Revenue
PART 31—EMPLOYMENT TAXES AND COLLECTION OF INCOME TAX AT SOURCE
Subpart E—Collection of Income Tax at Source
§ 31.3402(g)-2 Wages paid for payroll period of more than one year.