A sole proprietor can take the standard deduction, and for 2026 that amount is $16,100 for single filers, $32,200 for married couples filing jointly, and $24,150 for heads of household. The sole proprietorship standard deduction works the same way it does for any individual taxpayer, because a sole proprietorship isn’t taxed as a separate entity. Business profit lands on your personal Form 1040, and the standard deduction reduces that combined income on the personal side of the return. It has nothing to do with your business expenses, which come off earlier and separately on Schedule C.
Business Expenses Come Off First, on Schedule C
Every sole proprietor reports revenue and expenses on Schedule C. Gross income from selling goods or providing services goes at the top, and ordinary and necessary business expenses come off to produce net profit.1Internal Revenue Service. Topic No. 407 – Business Income Common categories include advertising, professional fees, supplies, utilities, cost of goods sold, and business insurance. Owners who drive for business can use the IRS standard mileage rate of 72.5 cents per mile for 2026 instead of tracking actual vehicle costs.2Internal Revenue Service. The Standard Mileage Rates and Maximum Automobile Fair Market Values Have Been Updated for 2026
A home office used regularly and exclusively for business is also deductible on Schedule C. The simplified method allows $5 per square foot, up to 300 square feet, for a maximum deduction of $1,500 with no depreciation calculation. The regular method, reported on Form 8829, deducts actual expenses like mortgage interest, insurance, and utilities based on the business-use percentage of the home.3Internal Revenue Service. Simplified Option for Home Office Deduction
Net profit from Schedule C line 31 flows to Schedule 1 of Form 1040 and into your adjusted gross income.4Internal Revenue Service. Schedule C (Form 1040) – Profit or Loss From Business (Sole Proprietorship) Only after that does the standard deduction enter the picture. You never choose between deducting a business expense and taking the standard deduction. You get both.
2026 Standard Deduction Amounts
The standard deduction is a fixed dollar amount subtracted from AGI to lower taxable income. For 2026:5Internal Revenue Service. Revenue Procedure 2025-32
- Single or married filing separately: $16,100
- Married filing jointly: $32,200
- Head of household: $24,150
Taxpayers 65 or older or blind receive an additional amount on top of the base. Unmarried filers get an extra $2,050 per qualifying condition, and married filers get $1,650 per qualifying individual per condition. A married couple where both spouses are 65 or older adds $3,300 to their standard deduction, bringing the total to $35,500.5Internal Revenue Service. Revenue Procedure 2025-32
Standard Deduction or Itemized — Not Both
On the personal side of the return, you choose between the standard deduction and itemizing on Schedule A. Itemizing pays off only if your deductible personal expenses — state and local taxes, mortgage interest, charitable contributions, and similar items — add up to more than your standard deduction. After the increases enacted under the Tax Cuts and Jobs Act and extended by the One Big Beautiful Bill Act, the standard deduction is the better deal for most sole proprietors.
The choice here is a personal one and does not affect your Schedule C at all. Business expenses on Schedule C are neither “itemized” in the Schedule A sense nor part of the standard deduction calculation. They are a separate category entirely.
The Standard Deduction Doesn’t Reduce Self-Employment Tax
This is the point that trips people up. The standard deduction reduces your income tax. It does not reduce your self-employment tax. Self-employment tax funds Social Security and Medicare and is calculated on Schedule SE from your net business profit, before the standard deduction ever enters the return.6Internal Revenue Service. Schedule SE (Form 1040) – Self-Employment Tax The combined rate is 15.3%, covering both the employer and employee shares of Social Security (12.4%) and Medicare (2.9%).
So a large standard deduction can zero out your income tax and still leave you owing thousands in self-employment tax. If you want to shrink self-employment tax, you do it by legitimately reducing net profit on Schedule C, not by anything you claim later on Form 1040.
How the QBI Deduction Stacks With the Standard Deduction
The Qualified Business Income deduction under Section 199A lets sole proprietors deduct up to 20% of qualified business income.7Internal Revenue Service. Qualified Business Income Deduction It was originally scheduled to expire after 2025 but was extended by the One Big Beautiful Bill Act, signed into law on July 4, 2025.8Internal Revenue Service. One, Big, Beautiful Bill Provisions
The QBI deduction is not an above-the-line deduction. It doesn’t reduce AGI. Instead, it comes off alongside the standard deduction to arrive at taxable income. You take both, not one or the other.9Office of the Law Revision Counsel. 26 U.S.C. 199A – Qualified Business Income For most sole proprietors with taxable income below certain thresholds, the full 20% is available. Above those thresholds the calculation gets more complex, particularly for specified service businesses like law, accounting, health care, and consulting, and the deduction can phase out entirely at higher income levels.
The Order the Numbers Flow
Understanding the sequence is the whole point. First, net business profit is calculated on Schedule C by subtracting business expenses from gross revenue. That profit flows to Schedule 1 of Form 1040. Next, above-the-line adjustments, including the deductible half of self-employment tax, self-employed health insurance premiums,10Internal Revenue Service. Instructions for Form 7206 (2025) and retirement contributions, reduce that figure to reach AGI. Then the standard deduction (or itemized deductions) and the QBI deduction both come off AGI to produce taxable income. Income tax is calculated on that final figure. Self-employment tax runs on a parallel track, calculated on Schedule SE from net business profit before any of those personal deductions touch it.
Consider a sole proprietor earning $90,000 in net profit in 2026 and filing as single. The deductible half of self-employment tax (roughly $6,350) reduces AGI to about $83,650. The $16,100 standard deduction and a roughly $16,730 QBI deduction together bring taxable income down to about $50,820. Income tax gets calculated on that $50,820. Self-employment tax was already calculated separately on the full $90,000 of net profit, and the standard deduction did nothing to reduce it.