Your friend and you can split the cost of your trip expenses in several ways including: Equal split, Proportional split, personal Split. Business travel expenses are tax deductible (for the most part), meaning you could lower the taxes you need to pay.If you want to deduct your business expenses, you must complete Form 2106 and itemize your deductions. The entire trip consists of travel and business purposes. When it comes to business trips, the "Big 3" essentialstransportation, lodging, and mealsare your ticket to tax deduction city.