Self-Employed Tax Deductions: What You Can Actually Deduct

What we checked to reach this conclusion

We went directly to IRS publications, the Internal Revenue Code, and Schedule C instructions — not to tax-prep marketing copy, which has a financial incentive to oversimplify. We then cross-referenced against current tax court cases and CPA guidance to identify the deductions that routinely survive audit scrutiny versus those that raise flags. The standard we applied: would a reasonable CPA advise this, and does the IRS's own published guidance back it up?

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  IRS Publication 535 (Business Expenses) reviewed Confirmed which expense categories qualify as "ordinary and necessary" under IRC §162 and the conditions each must meet to be deductible.
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  Schedule C and Schedule SE instructions verified Confirmed the correct forms and lines for reporting self-employment income, business deductions, and the SE tax deduction — including the half-SE-tax deduction that many filers miss.
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  IRS standard mileage rate confirmed for 2025 tax year The IRS set the business standard mileage rate at 70 cents per mile for 2025 (returns filed in 2026), confirmed via IRS Notice 2025-5.
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  Home office deduction rules cross-checked against IRS Form 8829 instructions Confirmed the "regular and exclusive use" requirement, the two calculation methods, and that renters qualify just as homeowners do.
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  Health insurance and retirement contribution deduction limits verified Confirmed the self-employed health insurance deduction under IRC §162(l) and the 2025 SEP-IRA contribution ceiling ($70,000 or 25% of net self-employment income, whichever is less).

Different situations call for different approaches — here's how to choose

How aggressively you can deduct depends on how organized your records are, what kind of self-employment you do, and whether you're comfortable filing yourself or want a professional backstop.

What people try to deduct that the IRS won't accept

A lot of bad deduction advice circulates online because the people sharing it never got audited — not because the advice is correct. These are the most common mistakes that create real problems.

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  Deducting your entire home as a home office — The IRS requires that the space be used regularly and exclusively for business; a kitchen table where you also eat dinner, or a guest room that occasionally has a desk in it, doesn't qualify — and overclaiming the home office deduction is one of the most reliable ways to trigger a closer look at your return.
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  Deducting personal meals as business meals — Business meals are only 50% deductible when they involve an actual business discussion with a client, customer, or business contact — eating lunch alone at your desk while working does not qualify, and the "meals while working from home" deduction that circulated on social media has no basis in the tax code.
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  Claiming your entire phone and internet bill — If you use your personal phone and home internet for both work and personal use — which almost everyone does — you can only deduct the business-use percentage, not the full bill; claiming 100% without documentation to support it is a red flag that auditors specifically look for.
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  Forgetting to pay quarterly estimated taxes and then trying to deduct the penalties — Self-employment tax penalties for underpayment are not deductible, so skipping quarterly payments (due in April, June, September, and January) and paying everything at filing time costs you money twice — in penalties and in lost float on funds you could have kept working for you longer.