When you go on a business trip to the United States and tack on some vacation days, you can usually deduct some of your expenses. But exactly what can you write off?

Deduction for Transportation Expenses
Transportation costs to and from the location of your business activity are always 100% deductible as long as the primary reason for the trip is business. However, if vacation is the primary reason for your travel, then none of your transportation expenses are deductible.

Costs that can be included as expenses are travel to and from your departure airport, airfare, baggage fees, tips, cabs, and so forth. Costs for public transportation or driving your personal car are also appropriate.

Deduction for Business Days vs. Pleasure Days
The number of days spent on business versus pleasure is a key factor in determining if the primary reason for travel is business. Your travel days count as business days, as do weekends and holidays if they fall between business days, and it would be impractical to return home.

Standby days, or days when your physical presence is required, also count as business days, even if you aren’t called in to work those days. Any other day devoted to business activities during normal business hours also counts as a business day. This includes days when you were going work but couldn’t due to reasons beyond your control.

If business days exceed personal days, you should be able to claim business as the primary reason for a domestic trip. Be sure to gather proof and keep it with your tax records. For instance, if your trip is to attend client meetings, log everything in your daily planner and copy the pages for tax filings. If you attend a conference or training seminar, keep the program and take notes to show you attended.

Once you’re at the destination, out-of-pocket expenses for business days are fully deductible. These expenses may include lodging, hotel tips, meals (subject to the 50% disallowance rule), seminar, conference fees, and cab fare. Expenses for personal days are always nondeductible.

Find Answers to Your Tax Questions
Equipping yourself with some basic business expense knowledge and implementing a system to take advantage of them is vital when traveling on business.

If you’re unsure what to deduct or need further assistance with your travel expenses, you should contact a knowledgeable advisor before you do your taxes this season.