Step 1. Determine an average wage for each of such payroll periods by dividing the sum of the supplemental wages and the wages paid for such payroll periods by the number of such payroll periods.
Step 2. Determine a tax for each payroll period as if the amount of the average wage constituted the wages paid for such payroll period.
Step 3. From the sum of the amounts of tax determined in Step 2 subtract the total amount of tax withheld, or to be withheld, from the wages, other than the supplemental wages, for such payroll periods. The remainder, if any shall constitute the amount of the tax to be withheld upon the supplemental wages.
Example. An employee has a weekly payroll period ending on Saturday of each week, the wages for which are paid on Friday of the succeeding week. On the 10th day of each month he is paid a bonus based upon production during the payroll periods for which wages were paid in the preceding month. The employee is paid a weekly wage of $64 on each of the five Fridays occurring in July 1966. On August 10, 1966, the employee is paid a bonus of $125 based upon production during the five payroll periods covered by the wages paid in July. On the date of payment of the bonus, the employee, who is married and has three children, has a withholding exemption certificate in effect indicating that he is married and claiming five withholding exemptions. The amount of the tax to be withheld from the bonus paid on August 10, 1966, is computed as follows:
Wages paid in July 1966 for 5 payroll periods (5 * $64) | $320.00 |
Bonus paid August 10, 1966 | 125.00 |
Aggregate of wages and bonus | 445.00 |
Average wage per payroll period ($445 ÷ 5) | 89.00 |
Computation of tax under percentage method: Withholding exemptions (5 * $13.50) | 67.50 |
Remainder subject to tax | 21.50 |
Tax on average wage for 1 week under percentage method of withholding (married person with weekly payroll period) 14 percent of $17.50 (excess over $4)) | 2.45 |
Tax on average wage for 5 weeks | 12.25 |
Less: Tax previously withheld on weekly wage payments of $64 | None |
Tax to be withheld on supplemental wages | 12.25 |
Computation of tax under wage bracket method: Tax on $89 wage under weekly wage table for married person ($2.50 per week for 5 weeks) | 12.50 |
Less: Tax previously withheld on weekly wage payments of $64 | None |
Tax to be withheld on supplemental wages | 12.50 |
26 C.F.R. §31.3402(g)-1