Tax & Compliance
Mileage payment that is not taxable when it follows accountable-plan rules.
A mileage reimbursement is tax-free when (1) there is a business purpose, (2) the expense is substantiated within a reasonable period, and (3) any excess advance is returned. Under those conditions the IRS, SAT, Receita Federal, and peers treat the payment as a refund of expense, not income — no FICA, no IRPF, no ISR. Failing any test reclassifies the full amount as taxable wages.