Donna Genie breaks down the deductions small-business owners miss most: home office (simplified $5 per square foot or actual expenses) and vehicle mileage (72¢ to 76¢ per mile in 2026). Many have hard year-end deadlines you can't reclaim later, and claiming them won't trigger an audit.
The tax rules are written for business owners. Most of them just never read them. And that's why every year people who work harder than anybody pay more taxes than they ever had to. Not because they did anything wrong, but because they missed things. Here's what makes it worse. Most of these write-offs have a deadline. If you don't do them by December 31st, you lose them for the year and you can't fix it in April. So today I'm going to show you the write-offs that business owners miss the most, what's new for 2026, and what to do before the year ends. A lot of owners skip this because someone told them it gets you audited. That is just not true. If you have space in your home that you regularly and exclusively use for your business, you're allowed to write it off. That's the rule, not a trick. The easy way is $5 for every square foot up to $300 or up to 300 square feet. So that's up to $1,500 a year. Or you can write off part of your real home bills like rent. Utilities, insurance, based on how much of your home the office actually takes up. Measure the room and take a picture. That's your proof. Now your car. Most people don't track their business driving at all, or they don't know that they have a choice in how to write it off. You do have 2 choices. The first is a set amount for every business mile you drive. For 2026, that started out at 72 cents a mile, 72.5 cents a mile, and on July 1st, it went up to 76 cents a mile because Gasoline got more expensive.
