Meal expenses are deductible only if your trip is overnight or long enough that you need to stop for sleep or rest to properly perform your duties. The amount of the meal expenses must be substantiated, but instead of keeping records of the actual cost of your meal expenses you can generally use a standard meal allowance. The amount allowed varies, depending on where and when you travel. Refer to Publication 1542, Per Diem Rates (For Travel Within the Continental United States), for per diem rates.

Generally, the deduction for unreimbursed business meals is limited to 50% of the cost that would otherwise be deductible.

For more information on business travel expenses and restrictions, refer to Tax Topic 511, or Publication 463, Travel, Entertainment, Gift, and Car Expenses, and Publication 1542, Per Diem Rates .