7 Tax Deductions Small Business Owners Almost Always Miss

January 2026 · 5 min read

Most small business owners aren't missing deductions because they're careless, they're missing them because nobody ever explained what actually qualifies. Here are seven that come up again and again.

1. Home office deduction

If you have a space used regularly and exclusively for business, even a corner of a room, you can likely deduct a portion of your rent or mortgage, utilities, and related costs.

2. Mileage

Driving to meet clients, pick up supplies, or run business errands all counts. Track it consistently (an app works fine) and it adds up faster than people expect.

3. Health insurance premiums

If you're self-employed and paying for your own health insurance, those premiums are often fully deductible, one of the larger deductions many people don't realize applies to them.

4. Software and subscriptions

Accounting software, design tools, project management apps, anything you pay for to run your business counts, even smaller recurring charges.

Why this matters more than people think: A handful of small, recurring software subscriptions can easily total $1,000 to $2,000 a year. That's real money if it's been missed.

5. Portion of phone and internet

If you use your personal phone or home internet for business, you can deduct the business-use percentage, not the whole bill, but a reasonable, defensible portion.

6. Professional development

Courses, books, and conferences related to your field are generally deductible, an often-missed category for people investing in their own skills.

7. Retirement contributions

Contributions to a SEP-IRA or Solo 401k aren't just smart for your future, they directly lower your taxable income today.

The common thread: most of these require decent records, not perfect ones. A simple habit of tracking expenses monthly (rather than reconstructing everything in March) is what actually captures these deductions.

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