A per diem allowance for meal and incidental expenses (M&IE) only may be used to substantiate an employee's or other payee's M&IEs for purposes of the employer's return (Rev. Proc. 2011-47). The amount that is deemed substantiated is equal to the lesser of the per diem allowance or the amount computed at the federal M"&IE rate for the locality of travel for the period that the employee is away from home. If M&IEs are substantiated using a per diem allowance, the entire amount is treated as a food and beverage expense subject to the 50-percent limitation on meal and entertainment expenses.
The M&IE rate must be prorated for partial days of travel away from home. If an employee's meals are provided by the employer, even though the employee may be working from home, the employee is entitled to deduct only the incidental expense portion of the applicable federal per deim M&IE rates (R.J. Zbylut, Dec. 57,348(M), 95 TCM 1172 (2008)).
Self-Employed Persons and Employees. Self-employed individuals and employees whose expenses are not reimbursed may also use the M&IE-only rate to substantiate M&IEs while traveling away from home. The taxpayer must actually prove through adequate records or sufficient corroborative evidence the time, place, and business purpose of the travel, and lodging costs.
Optional Method for Incidental-Expense-Only Deduction. Taxpayers may use an optional method to deduct only incidental expenses in lieu of using actual expenses. Taxpayers who do not incur any meal expenses may deduct $5 per calendar day (or partial day) as ordinary and necessary incidental expenses, paid or incurred, while traveling to any localities within the continental United States (CONUS) or outside the continental United States (OCONUS) (Notice 2017-54, Notice 2016-58). The optional method is subject to the proration rules for partial days and substantiation requirements for taxpayers who use the per diem method for substantiation (Rev. Proc. 2011-47). The optional method for incidental expenses only cannot also be used by taxpayers who use the lodging plus M&IE per diem method, the M&IE-only method, or the high-low method and the optional M&IE-only mnethod
Transportation Workers. The M&IE rates for travel awy from home on or after October 1, 2017, for both self-employed persons and employees in the transportation industry are $63 for CONUS localities and $68 for OCONUS localities. The M&IE rates for travel away from home on or after October 1, 2016, for both self-employed persons and employees in the transpotation industry are $63 for CONUS localities and $68 for OCONUS localities (Notice 2017-54, Notice 2016-58). An individual is in the transportation industry only if the individual's work: (1) directly involves moving people or goods by airplane, barge, bus, ship, train, or truck; and (2) regularly requires travel away from home that involves travel to localities with differing federal M&IE rates during a single trip.
Under a calendar-year convention for the transportation industry, taxpayers who used the federal M&IE rates during the first nine months of calendar year2017 to substantiate an individual's travel expenses may not use the special transportation industry rates for that individual until January 1, 2018 (Rev. Proc. 2011-47). Likewise, taxpayers who used the special transportation industry rates for the first nine months of calendar year 2017 to substantiate an individual's travel expenses may not use the federal M&IE rates for that individual until January 1, 2018.