In this article
Last updated: May 27, 2026 · Reading time: 9 minutes
The small business tax deductions most owners miss are: the home office deduction, vehicle mileage, a portion of phone and internet, half of self-employment tax, self-employed health insurance, the 20% Qualified Business Income (QBI) deduction, startup costs, bank/processing fees, and retirement contributions (SEP-IRA / Solo 401k). Each one reduces the net profit you're taxed on — so tracking them is the same as giving yourself a raise.
You're taxed on profit, not revenue
Every legitimate expense you record lowers your taxable profit. A missed $1,000 deduction at a ~25% combined rate is about $250 handed to the IRS unnecessarily. Across a year of small misses, that adds up to real money. Here are the ones owners most commonly leave on the table.
15 commonly-missed small business deductions
| # | Deduction | What to know |
|---|---|---|
| 1 | Home office | Simplified method: $5/sq ft up to 300 sq ft ($1,500 max). Must be used regularly & exclusively for business. |
| 2 | Vehicle mileage | Standard rate (2026: $0.70/mile — verify at IRS.gov) OR actual expenses. Needs a contemporaneous log. |
| 3 | Phone & internet (business %) | Deduct the business-use percentage of your cell and home internet. |
| 4 | Half of self-employment tax | Automatically deductible against income tax — many forget it exists. |
| 5 | Self-employed health insurance | Premiums for you, spouse, dependents — if not eligible for an employer plan. |
| 6 | QBI deduction (Section 199A) | Up to 20% of qualified business income, subject to income limits. |
| 7 | Startup costs | Up to $5,000 of startup + $5,000 organizational costs deductible in year one. |
| 8 | Bank & payment-processing fees | Stripe/PayPal/Square fees, business bank fees — fully deductible. |
| 9 | Retirement contributions | SEP-IRA or Solo 401(k) contributions reduce taxable income substantially. |
| 10 | Software & subscriptions | Invoicing apps, design tools, cloud storage used for business. |
| 11 | Education & training | Courses, certifications, books that maintain/improve current business skills. |
| 12 | Business insurance | General liability, professional liability, commercial auto. |
| 13 | Marketing & advertising | Ads, yard signs, business cards, website hosting, listing fees. |
| 14 | Section 179 equipment expensing | Expense qualifying equipment in year one instead of depreciating (2026 limit: $1,250,000 — verify). |
| 15 | Business meals (50%) | Meals with clients or during business travel — 50% deductible, keep the receipt + purpose. |
The deductions people get wrong (and the IRS checks)
- Home office: "regularly and exclusively" is strict. A kitchen table you also eat dinner at doesn't qualify.
- 100% vehicle use: almost nobody drives a vehicle 100% for business. 80–85% is more defensible for a work truck.
- Meals: only client meals or travel meals — lunch alone at your desk isn't deductible.
- Clothing: only deductible if it's a genuine uniform or branded — regular clothes you could wear elsewhere aren't.
The real secret: it's a tracking problem, not a tax problem
Most missed deductions aren't missed because owners don't know about them — they're missed because the receipt got lost or the expense was never recorded. The fix is a habit: capture every expense the moment it happens. Snap the receipt, categorize it, move on. At tax time you export the totals by category and nothing's missing.
Frequently asked questions
What is the most overlooked small business tax deduction?
The home office deduction and the deductible half of self-employment tax are the two most commonly missed. The home office (simplified method) is worth up to $1,500, and half your SE tax is automatically deductible but easy to forget.
What is the QBI deduction?
The Qualified Business Income deduction (Section 199A) lets eligible pass-through business owners deduct up to 20% of their qualified business income, subject to income thresholds and business-type limits. It's one of the largest deductions available to small businesses.
Can I deduct my cell phone and internet?
Yes — the business-use percentage. If your phone is 70% business, deduct 70% of the bill. Keep a reasonable basis for the percentage you claim.
How do I make sure I don't miss deductions?
Track every business expense as it happens rather than reconstructing at year-end. Use a receipt scanner to capture and categorize purchases immediately, and review your expense categories monthly so nothing slips through.
Daily Invoice Maker's AI receipt scanner captures and categorizes expenses in seconds, tracks mileage, and exports a Schedule-C-ready report — so the deductions you earned actually make it onto your return. $149.95 lifetime or $5.95/month, works offline.
Capture every receipt →This article is general educational information, not tax, legal, or accounting advice. Tax rates, limits, and thresholds change every year and sometimes mid-year — verify all current figures at IRS.gov and consult a licensed CPA or enrolled agent for your specific situation.
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