If you’re self-employed, you can write off business expenses on your personal taxes by filing Schedule C with your Form 1040. Your gross business income minus your deductible expenses equals net profit, and only that net profit flows into your taxable income. Every legitimate business expense reduces both your income tax and your self-employment tax, which makes getting these deductions right the single most effective way to lower what you owe.
Who Can Actually Do This
The Schedule C path is for people earning income through self-employment: freelancers, independent contractors, and sole proprietors. Partners in a partnership and members of multi-member LLCs report through a Schedule K-1 instead. S corporation and C corporation owners deduct expenses at the entity level, not on their personal return.
If you’re a W-2 employee, the answer is almost always no. The permanent elimination of miscellaneous itemized deductions means most employees cannot deduct unreimbursed business expenses on their personal return at all. A narrow set of exceptions covers Armed Forces reservists, qualified performing artists, fee-basis state or local government officials, and employees with impairment-related work expenses. Everyone else who receives a W-2 has no path to writing off business costs personally, even for things their employer refused to reimburse.
What Counts as a Deductible Business Expense
Federal law allows a deduction for expenses that are “ordinary and necessary” to your trade or business.1Office of the Law Revision Counsel. 26 USC 162 – Trade or Business Expenses An ordinary expense is one that’s common in your line of work. A necessary expense is one that’s helpful and appropriate for the business, even if you could technically operate without it.
That definition covers a lot: software subscriptions, professional liability insurance, advertising, office supplies, accounting fees, business phone lines, website hosting, and professional development. If you can draw a straight line between the expense and generating business income, it likely qualifies.
Personal expenses never qualify, even when they happen near business activity. Commuting from home to a regular workplace isn’t deductible. Clothing you could wear outside work doesn’t count. Personal grooming, meals eaten alone with no business purpose, and side trips during a business trip are all out. The dividing line is whether the expense exists because of the business or because of your personal life.
How Schedule C Turns Expenses Into Tax Savings
Schedule C, titled “Profit or Loss From Business,” is where all self-employment income and expenses live.2Internal Revenue Service. About Schedule C (Form 1040) Part I collects all business income: payments from clients, 1099 income, cash sales, everything. Part II is where you list deductible expenses by category. The difference is your net profit or loss, calculated on Line 31. That number transfers to your Form 1040 and becomes part of your adjusted gross income.3Internal Revenue Service. About Form 1040 U.S. Individual Income Tax Return
Lowering net profit through legitimate deductions doesn’t just cut your income tax. A lower AGI can improve your eligibility for education credits, health insurance premium subsidies, and other income-based benefits.
Why These Deductions Matter Twice
Your Schedule C net profit also triggers self-employment tax, calculated on Schedule SE.4Internal Revenue Service. About Schedule SE (Form 1040) This funds Social Security and Medicare. You pay both the employer and employee halves at a combined rate of 15.3%: 12.4% for Social Security and 2.9% for Medicare.5Office of the Law Revision Counsel. 26 USC 1401 – Rate of Tax
The tax applies to 92.35% of your net self-employment earnings. The 12.4% Social Security portion applies only up to $184,500 in earnings for 2026.6Social Security Administration. What Is the Current Maximum Amount of Taxable Earnings for Social Security The 2.9% Medicare portion has no cap, and an additional 0.9% Medicare surtax applies on self-employment income above $200,000 for single filers, $250,000 for married filing jointly, or $125,000 for married filing separately.7Internal Revenue Service. Questions and Answers for the Additional Medicare Tax
Because expenses on Schedule C reduce the number that both income tax and SE tax are calculated from, each dollar deducted usually saves you significantly more than a dollar deducted elsewhere on your return. You can also deduct half of your total SE tax as an adjustment to income on Schedule 1.
Expenses That Are Part Business, Part Personal
When an asset serves both your business and your personal life, only the business portion is deductible. The two most common cases are your home and your vehicle.
Home Office
To claim a home office deduction, you need a specific area of your home used exclusively and regularly as your principal place of business.8Office of the Law Revision Counsel. 26 USC 280A – Disallowance of Certain Expenses in Connection With Business Use of Home The exclusive-use test is strict. A desk in a room that doubles as a guest bedroom fails. Exceptions apply if you meet clients in the space in the normal course of business or if you use a separate freestanding structure.9Internal Revenue Service. Topic No. 509 Business Use of Home
Two calculation methods are available. The simplified method gives you $5 per square foot up to 300 square feet, for a maximum deduction of $1,500.9Internal Revenue Service. Topic No. 509 Business Use of Home The actual expense method uses the percentage of your home the office occupies, applied to your mortgage interest or rent, property taxes, utilities, insurance, and repairs. The actual method usually produces a larger deduction but requires more recordkeeping and involves depreciating the business portion of your home. When you eventually sell, that depreciation gets taxed at a rate up to 25%, even if the rest of your home sale gain qualifies for the capital gains exclusion. The simplified method sidesteps that recapture because no depreciation is claimed.
Vehicle Use
If you use a personal vehicle for business, you deduct the business-use portion. You pick a method in the first year you put the vehicle into business service: the standard mileage rate or the actual expense method.10Internal Revenue Service. Topic No. 510 – Business Use of Car
The standard mileage rate for 2026 is 70 cents per mile driven for business.11Internal Revenue Service. Standard Mileage Rates That flat rate covers gas, maintenance, insurance, and depreciation. Tolls and business-related parking are deductible on top of it. The actual expense method requires tracking every vehicle cost and multiplying total costs by the business-use percentage of your miles.
Either way, you need a mileage log recording the date, destination, business purpose, and distance for every business trip. This is one of the most audit-prone areas of a self-employed return, and “I drive a lot for work” doesn’t hold up without contemporaneous records.
Equipment, Insurance, Retirement, and QBI
A handful of larger deductions are worth knowing about because they often produce more savings than the day-to-day expense categories combined.
Equipment and Property
When you buy equipment, furniture, or computers for the business, you can normally spread the deduction over the asset’s useful life, or you can accelerate it. Section 179 lets you deduct the full purchase price of qualifying business assets in the year you buy and start using them, up to $2,560,000 for 2026, with a phase-out beginning at $4,090,000 in total qualifying purchases.12Internal Revenue Service. Publication 946 (2025), How To Depreciate Property Section 179 can’t create or increase a loss. Bonus depreciation is a parallel rule that allows a 100% deduction on eligible property acquired and placed in service after January 19, 2025, and, unlike Section 179, it can create or increase a net operating loss. For most self-employed taxpayers buying laptops, furniture, or tools, both approaches achieve the same result: full cost deducted in year one.
Health Insurance
If you pay for your own health insurance and aren’t eligible for coverage through a spouse’s employer plan, you can deduct premiums for medical, dental, and vision insurance for yourself, your spouse, and your dependents. This deduction goes on Schedule 1 of Form 1040, calculated using Form 7206, not on Schedule C.13Internal Revenue Service. About Form 7206, Self-Employed Health Insurance Deduction The deduction can’t exceed your net self-employment income from the business the plan is established under.
Retirement Contributions
Self-employed retirement plans double as significant tax deductions. A SEP-IRA allows contributions up to 25% of your net self-employment earnings, with a $72,000 cap for 2026.14Internal Revenue Service. SEP Contribution Limits (Including Grandfathered SARSEPs) A Solo 401(k) has the same $72,000 ceiling for those under 50 but splits contributions into an employee deferral portion up to $24,500 and an employer profit-sharing portion up to 25% of net earnings. Catch-up contributions are available at 50 or older.
Qualified Business Income
Separate from Schedule C, you may qualify for the Qualified Business Income deduction, which lets you deduct up to 20% of qualified business income from your taxable income. It sits on your Form 1040, not on Schedule C, so it reduces income tax only, not self-employment tax. The full 20% is available with taxable income below $201,750 for single filers or $403,500 for married filing jointly in 2026. A phase-out applies above those thresholds, and service-based businesses like law, accounting, consulting, and health care face tighter limits within the phase-out range.
The 50% Rule on Business Meals
Business meals are deductible at 50% of the cost, provided the meal isn’t lavish and you or your employee are present when the food is served.15Internal Revenue Service. Small Business and Self-Employed Income and Expenses The temporary 100% deduction for restaurant meals from 2021 and 2022 has expired.16Internal Revenue Service. Here’s What Businesses Need to Know About the Enhanced Business Meal Deduction
Documentation matters more here than in almost any other category. For every business meal, record the amount, date, location, business purpose, and the name and business relationship of each person present. “Lunch with client” scrawled on a receipt won’t survive an audit. “Lunch with Sarah Chen, discussed Q2 deliverables for web redesign project” will.
The Hobby Trap That Kills All Your Deductions
If the IRS decides your activity is a hobby rather than a genuine business, you lose the ability to deduct expenses entirely. This isn’t a partial haircut. Hobby expenses aren’t deductible under current law, and you still owe tax on any income the activity brings in.
The IRS presumes an activity is a business if it turns a profit in at least three of the last five tax years.17Internal Revenue Service. Is Your Hobby a For-Profit Endeavor? Failing that benchmark doesn’t automatically make you a hobby, but it shifts the burden to you. The IRS looks at whether you keep businesslike records, the time and effort you put in, whether you depend on the income, and whether losses reflect startup-phase circumstances or a persistent pattern. If you’re running a business that regularly shows losses, keep records showing how you’re trying to become profitable: business plans, marketing efforts, adjustments to your model, professional development.
Records the IRS Will Actually Accept
Every deduction on your Schedule C needs documentation. Receipts, bank statements, mileage logs, contracts, invoices. Digital records are legally equivalent to paper originals as long as the images are accurate, legible, and retrievable on demand.
How long you keep records depends on the situation, but three years from the filing date covers most self-employed taxpayers. If you underreport income by more than 25% of your gross income, the IRS has six years to audit. Records related to property (equipment, vehicles, your home if you claim an office deduction) need to be kept until the statute of limitations expires for the year you sell or dispose of the asset, which can mean holding depreciation records for decades.18Internal Revenue Service. How Long Should I Keep Records?
The cheapest insurance against an audit is a habit of recording expenses as they happen. Reconstructing a year’s worth of business expenses after the fact is miserable work, and the gaps always seem to land on your most defensible deductions.