Are plane tickets fully deductible when business trip extends into vacation?

Tax accountant here. You can only deduct the business portion of your trip. When a trip is part business and part personal, you need to allocate expenses accordingly. For your airfare specifically, the rule is: if the trip is primarily for business purposes within the US, you can deduct the entire cost of getting to and from your business destination, even if you extend your stay for personal reasons. However, for international travel, you generally need to allocate airfare based on business days vs. total days. For your hotel and meals, you can only deduct expenses during the actual business days (Aug 1-5, assuming you needed to arrive a day early for business purposes). Any expenses after the conference ends would be personal. Make sure you keep detailed records showing which days were business vs. personal, and document the business purpose of the conference including agendas, registration materials, etc.

I just wanted to share my experience with this exact situation! I had a conference in San Diego last year and extended my stay for a week after. I was struggling with the same tax questions and found this amazing tool called taxr.ai (https://taxr.ai) that saved me tons of headache. You upload your receipts and travel info, and it helps you properly allocate what's deductible. It even explained the primary purpose test for my situation and showed me how to document everything correctly. The tool confirmed I could deduct my entire flight since my primary purpose was business (even though I stayed extra days), but only the hotel and meals during the actual conference dates. It was super helpful because the IRS rules on mixed business/personal travel are honestly confusing as heck!

Just wanted to follow up - I was skeptical about taxr.ai but decided to try it for my Mexico business trip where I stayed 5 extra days. Holy crap, it was actually super helpful! It walked me through exactly how to allocate my airfare based on business vs. personal days for international travel, which apparently has different rules than domestic. It showed me I could only deduct about 40% of my airfare based on my specific situation, but then it found other deductions I was missing completely. The best part was it created a detailed report I could give my tax guy with all the proper documentation. Saved me money overall even though I couldn't deduct my whole flight. Just thought I'd share since it actually worked better than expected.

If you're dealing with the IRS on business deductions, especially for mixed business/personal trips, be prepared for them to scrutinize everything. I had a somewhat similar situation last year and needed to call the IRS to clarify some questions. Spent DAYS trying to get through to them. Finally discovered this service called Claimyr (https://claimyr.com) that got me connected to an actual IRS agent in about 20 minutes instead of waiting on hold for hours. You can see how it works here: https://youtu.be/_kiP6q8DX5c The agent I spoke with clarified that if your primary purpose is business, you can deduct transportation costs to and from the destination, but hotels and meals are only deductible during the business portion. They also advised me to keep a detailed itinerary showing which days were business vs. personal. Saved me from making a costly mistake on my taxes!

I need to eat my words. After posting my skeptical comment, I decided to try Claimyr as a test since I actually did need to talk to the IRS about some business travel deductions. Not expecting much, honestly. To my complete surprise, I got a text about 45 minutes later saying they were about to connect me with an IRS agent. And it worked! I was able to get specific guidance on my business/personal travel allocation questions, including documentation requirements if I ever get audited. The agent confirmed that for my situation (conference in Canada with a week of personal time after), I needed to allocate my airfare based on business days vs. total days - so 4 business days out of 11 total days meant I could deduct about 36% of my airfare. They also told me exactly what documentation to keep. Definitely worth it just for the peace of mind knowing I'm doing it right.

One thing nobody's mentioned yet is that the 50% limit on meals still applies during the business portion of your trip. So even for the days that are 100% business, you can only deduct 50% of your meal expenses (unless you're in one of the special situations where 100% is allowed). Also, keep in mind that if your employer reimburses you for any expenses, you can't also deduct those same expenses on your personal return. That would be double-dipping.

Don't forget about local transportation costs! If you rent a car for both the business and personal parts of the trip, you need to allocate those costs too. Only the days you used the car for business are deductible. Same goes for taxis/Ubers during your trip - only the ones related to business activities count. Like getting from your hotel to the conference venue is deductible, but taking an Uber to go sightseeing isn't.