SECTION 10. WITHHOLDING AND

PAYMENT OF EMPLOYMENT TAXES

.01 The portion of a mileage allowance (other than a FAVR allowance), if any, that relates to the miles of business travel substantiated and that exceeds the amount deemed substantiated for those miles under section 9.01(1) of this revenue procedure is treated as paid under a nonaccountable plan and is subject to withholding and payment of employment taxes. See § 1.62–2(h)(2)(i)(B).

(1) In the case of a mileage allowance paid as a reimbursement, the excess described in section 10.01 of this revenue procedure is subject to withholding and payment of employment taxes in the payroll period in which a payor reimburses the expenses for the business miles substantiated. See § 1.62–2(h)(2)(i)(B)(2).

(2) In the case of a mileage allowance paid as an advance, the excess described in section 10.01 of this revenue procedure is subject to withholding and payment of employment taxes no later than the first payroll period following the payroll period in which the business miles for which the advance was paid are substantiated. See § 1.62–2(h)(2)(i)(B)(3). If some or all of the business miles for which the advance was paid are not substantiated within a reasonable period of time and the employee does not return the portion of the allowance that relates to those miles within a reasonable period of time, the portion of the allowance that relates to those miles is subject to withholding and payment of employment taxes no later than the first payroll period following the end of the reasonable period. See § 1.62–2(h)(2)(i)(A).

(3) In the case of a mileage allowance that is not computed on the basis of a fixed amount per mile of travel (for example, a mileage allowance that combines periodic fixed and variable rate payments, but that does not satisfy the requirements of section 8 of this revenue procedure), the payor must compute periodically (no less frequently than quarterly) the amount, if any, that exceeds the amount deemed substantiated under section 9.01(1) of this

2009–51 I.R.B. 936 December 21, 2009

ble volunteer pays or incurs on or after January 1, 2010.