Travel expenses that are deductible include any ordinary and necessary expenses incurred while traveling for business. The key words here again are ordinary and necessary. If you are flying first class and staying in five star hotels for every business trip, the IRS might not consider a hundred percent of your travel expenses to be ordinary and necessary. The same goes for a week-long trip to Hawaii, where you only had one business lunch. The IRS does in fact require the employee to provide substantiation for expenses over a certain per DM rate. And the same goes for travel expenses as meal expenses, the per DM rate threshold can vary by city and state. What is considered an ordinary and necessary expense can vary from taxpayer to taxpayer. So reach out to one of our tax managers today to discuss your situation more specifically.