What counts as a business trip?
A business trip is one trip taken for work, and the IRS has a specific test for what qualifies. This cheat sheet covers how to think about one, the math on a trip with personal days and the steps to plan it. The detail is further down.
How to think about it
- Sleep or rest is the test. You're traveling away from home if your duties keep you away substantially longer than an ordinary workday and you need sleep or rest to do the job. A nap in the car doesn't count.
- Same-day runs usually aren't trips. A truck driver who leaves the terminal and returns the same day, with only an hour off to eat, isn't traveling away from home under IRS rules.
- The main purpose decides. If a trip is entirely business, all of its travel costs can be deducted. If it's mainly personal, the whole trip is a personal expense, apart from business costs at the destination.
- Companions rarely count. Another person's costs are deductible only if they're your employee, have a real business reason to be there and could otherwise deduct the costs themselves.
The math
On a trip that's mainly business, the deductible cost is what the trip would have cost without the personal days.
Work in Atlanta, travel to New Orleans for business, and stop to visit family on the way home. The 9-day trip costs $2,165, but it would have taken 6 days without the stop, so the deductible amount.
$1,633.50
Illustrative example from IRS Publication 463. Meals within the deductible amount are subject to the 50% limit.
How to plan a business trip
- Set the objective and limitsWrite down why the trip is happening, which dates are fixed, the budget including taxes and fees, and which policy rules apply.
- Collect traveler details onceLegal names, Known Traveler numbers, loyalty IDs, payment method and emergency contacts, plus a project code so finance can reconcile by job.
- Sketch the itineraryMeeting times, airports, hotel locations that cut ground time, and transport or parking.
- Book the anchors firstLock meeting times, then flights, then hotels.
- Reconcile afterwardCollect folios, map them to codes and compare planned versus actual spend.
How it works on Engine
On Engine, Trips gives users one place to review previous and upcoming bookings, open and print itineraries, and start eligible changes or cancellations. Authorized users can book trips for coworkers, and View Only Travelers can sign in to see trips booked for them without booking or changing travel themselves.
Questions
Does a day trip count as a business trip?
Usually not for tax purposes. Under IRS rules, you're traveling away from home only if you're gone substantially longer than an ordinary workday and need sleep or rest to do the job.
Can I add vacation days to a business trip?
Yes. If the trip is mainly for business, you can deduct only the business-related costs, including getting to and from the business destination. The costs of the personal days aren't deductible.
Can I bring my spouse on a business trip?
You can, but their costs generally aren't deductible unless they're your employee, have a real business purpose for being there and could otherwise deduct the costs.
What records should I keep on a business trip?
Records of all your expenses and any advances from your employer. A log, diary, notebook or other written record works.
Sources
- Internal Revenue Service, Publication 463 (2025), Travel, Gift, and Car Expenses, accessed November 2, 2026.
- Engine, How to Book a Business Trip: A Practical, No-Fluff Guide, accessed November 2, 2026.
- Engine, 7 Productive Things You Can Do on a Business Trip, accessed November 2, 2026.
- Engine, Managing Business Trips With Engine, accessed November 2, 2026.
- Engine, Booking Travel for Coworkers, accessed November 2, 2026.