Every missed deduction is money you paid that you didn't have to. Here are the ones we see skipped most often. Each has rules, so keep records and ask before you claim.
Where you work and how you get there
- Home office. If part of your home is used regularly and exclusively for business, you may deduct actual expenses or use the simplified method ($5 per square foot, up to 300 square feet).
- Vehicle use. Track business miles and use the IRS standard mileage rate or actual expenses. A mileage log is essential.
- Phone and internet. The business-use share is deductible.
- Business travel. Transportation, lodging and 50% of meals on overnight business trips.
Taking care of yourself and your team
- Self-employed health insurance premiums for you, your spouse and dependents, if you qualify.
- Retirement contributions to a SEP, SIMPLE or solo 401(k). See 2026 limits.
- Employee benefits and education that relate to your business.
Running the business
- Startup costs: up to $5,000 in the first year, reduced once startup costs pass $50,000, with the rest spread out.
- Software and subscriptions, from accounting software to design tools.
- Bank, merchant and platform fees. Online sellers often record payouts net of fees and lose the deduction.
- Professional fees for accountants, attorneys and consultants.
- Business insurance premiums.
- Business meals with clients or prospects are generally 50% deductible (entertainment is not).
- Bad debts, for businesses using the accrual method.
- Equipment and improvements through Section 179 and 100% bonus depreciation. See year-end deductions.
And don't forget
The 20% qualified business income deduction for eligible pass-through owners, now permanent, and the domestic research and development deduction for businesses developing new products or software.
Clean monthly books are the best way to catch all of these. See our bookkeeping service.
This article is general information, current as of September 2026, and is not tax, legal or financial advice for your situation. Tax rules change often. Talk with us before acting on anything here.