This guide takes the top corporate travel expense questions and answers them for you. After you complete the form.Limits on employee business expenses. 1. It is the responsibility of the traveler to fill up the tank before returning the vehicle to the rental company. 6. Transportation Documentation. You can deduct travel expenses if they are ordinary (common and accepted in your business) and necessary (helpful and appropriate for your business). The actual costs of travel (for example, plane fare and cabs to the airport) are deductible for outoftown business trips. The State of Arizona Travel Policy is the guideline for all necessary and required travel to conduct the business of the State. This article explains four criteria required for trips to meet the IRS definition of deductible business travel. Do I need to fill out a Travel Authorization form for a webinar?