To deduct business expenses on your tax return, list the ordinary and necessary costs of running your business on Schedule C (Form 1040) if you’re self-employed, or through your entity’s return if you operate as a partnership or S corporation.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss From Business (Sole Proprietorship) Each qualifying expense reduces your taxable income dollar-for-dollar, and for self-employed filers it also lowers the base on which self-employment tax is calculated. The rules that decide what qualifies, how much, and on which form come from Internal Revenue Code Section 162 and a handful of related provisions.
What Qualifies as a Deductible Business Expense
Section 162 allows a deduction for “all the ordinary and necessary expenses paid or incurred during the taxable year in carrying on any trade or business.”2Office of the Law Revision Counsel. 26 USC 162 – Trade or Business Expenses Those two adjectives set the whole standard.
The Supreme Court in Welch v. Helvering defined an ordinary expense as one that is common and accepted in your specific trade.3Justia U.S. Supreme Court Center. Welch v. Helvering, 290 U.S. 111 (1933) It doesn’t have to recur daily; it has to be the sort of cost people in your line of work routinely face. A necessary expense is one that is helpful and appropriate for the business. It doesn’t have to be indispensable. If the spending makes practical sense for your operations and peers in your field spend on the same thing, it generally clears both tests.
Who Files Where
Sole proprietors, independent contractors, freelancers, and single-member LLCs report income and deductions on Schedule C attached to Form 1040.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss From Business (Sole Proprietorship) Partners and S corporation shareholders deduct business expenses through the entity’s return, not on personal Schedule C, though the ordinary-and-necessary standard is the same.
If you’re a W-2 employee, you generally cannot deduct unreimbursed job expenses on your federal return. The Tax Cuts and Jobs Act suspended that miscellaneous itemized deduction starting in 2018, and the One, Big, Beautiful Bill Act made the suspension permanent. Unreimbursed costs an employer won’t cover no longer produce a federal tax benefit.
Everyday Costs That Qualify
Most recurring costs of running a business clear the standard. Common categories include:
- Rent and utilities for office or workspace, including electricity, internet, and phone service used for the business.
- Insurance premiums for liability, property, and professional coverage tied to business operations.
- Professional fees paid to accountants, attorneys, and consultants for business work.
- Office supplies, software subscriptions, and raw materials used in the trade.
- Advertising and marketing, including website hosting, print ads, and online advertising.
- Business licenses and registration fees paid to state or local agencies.
- Bad debts owed by customers that become uncollectible, if you previously reported the amount as income.4Internal Revenue Service. Topic No. 453, Bad Debt Deduction
Vehicle costs get their own method. If you drive your personal car for business, you can use either the standard mileage rate or your actual vehicle expenses. The 2026 IRS standard mileage rate is 72.5 cents per business mile.5Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents Per Mile, Up 2.5 Cents Either way, keep a log with the date, destination, and business purpose of each trip.
Where the Limits Bite: Meals, Entertainment, and Gifts
Some categories are capped or blocked entirely, and these lines are among the most common audit triggers.
You can deduct 50% of a business meal when it has a clear business purpose, such as meeting with a client or traveling for work, provided it isn’t lavish or extravagant.6Office of the Law Revision Counsel. 26 USC 274 – Disallowance of Certain Entertainment, Etc., Expenses Keep the receipt and note who attended and what was discussed. Starting in 2026, employer-provided meals served on the business premises (like a company cafeteria) are no longer deductible at all, unless the employer is a restaurant or similar food-service business that also feeds its own workers.
Client entertainment is out. Sporting events, concerts, golf, and club memberships haven’t been deductible since the 2017 change, and that change is now permanent. If you take a client to a game and buy food there, the food is deductible at 50% only if the receipt separates it from the entertainment charge.
Business gifts are capped at $25 per recipient per year. Anything above that amount is not deductible.
Equipment and Other Capital Purchases
When you buy equipment, vehicles, furniture, or other assets with a useful life beyond one year, you generally can’t deduct the full cost the year you buy them. The default is depreciation under the Modified Accelerated Cost Recovery System, which spreads the deduction over the asset’s useful life. Two provisions let you accelerate that.
Under Section 179 for 2026, you can elect to immediately deduct up to $2,560,000 of qualifying equipment and property in the year you place it in service. The benefit begins to phase out once your total qualifying purchases exceed $4,090,000 for the year, and the deduction for a sport utility vehicle is capped at $32,000.7Internal Revenue Service. Revenue Procedure 2025-32 Your Section 179 deduction also cannot exceed your taxable business income for the year.
The One, Big, Beautiful Bill Act restored 100% bonus depreciation for qualifying property acquired after January 19, 2025, letting you deduct the entire cost of eligible new or used equipment in year one with no dollar cap.8Internal Revenue Service. One, Big, Beautiful Bill Provisions Unlike Section 179, bonus depreciation is not limited to your taxable income and can create or increase a net operating loss.
The Home Office Deduction
If you use part of your home exclusively and regularly as your principal place of business, you can deduct a portion of your housing costs. Section 280A requires the space be used only for business, so a room that doubles as a guest bedroom won’t qualify.9Office of the Law Revision Counsel. 26 USC 280A – Disallowance of Certain Expenses in Connection With Business Use of Home, Rental of Vacation Homes, Etc. A separate structure on your property, such as a converted detached garage, can qualify even if it isn’t your principal place of business.
You have two calculation methods. The simplified method multiplies $5 by the square footage of the office, up to 300 square feet, for a top deduction of $1,500, with no detailed tracking or depreciation calculations required.10Internal Revenue Service. Simplified Option for Home Office Deduction The actual expense method calculates the percentage of your home used for business and applies that percentage to real costs including mortgage interest, property taxes, utilities, insurance, and repairs. That method requires Form 8829 and more records but often produces a larger deduction for bigger workspaces.11Internal Revenue Service. Instructions for Form 8829 (2025)
Under either method, the home office deduction can’t exceed your gross business income for the year. With the actual expense method, any excess carries forward to the next year.
Startup Costs If You’re New
Costs incurred before your business opens, such as market research, launch advertising, employee training, and travel to find suppliers, don’t run through Schedule C like ongoing operating expenses. Under Section 195, you can deduct up to $5,000 of startup costs in the year the business begins operating. That $5,000 allowance is reduced dollar-for-dollar once total startup spending exceeds $50,000. Anything left is deducted in equal installments over the next 180 months (15 years).12Office of the Law Revision Counsel. 26 U.S. Code 195 – Start-Up Expenditures
Self-Employed Health Insurance
If you’re self-employed with a net profit and aren’t eligible for coverage through a spouse’s employer, you can deduct 100% of the premiums you pay for medical, dental, and vision insurance for yourself, your spouse, and your dependents, including qualified long-term care insurance. The plan must be established under your business or in your own name as a self-employed individual.13Internal Revenue Service. Instructions for Form 7206 (2025)
This one doesn’t go on Schedule C. You calculate it on Form 7206 and report it as an adjustment to income on Schedule 1 (Form 1040), line 17. It reduces income tax but not self-employment tax. You can’t claim it for any month you were eligible to participate in an employer-subsidized health plan, even if you didn’t enroll.
Filling In Schedule C
Schedule C opens with identifying information (your name, business name, and employer identification number or Social Security number), followed by gross income and expense sections.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss From Business (Sole Proprietorship) Part II lists specific expense categories like advertising, office supplies, travel, and utilities, each with its own line for the annual total. Costs that don’t fit a category go on the “other expenses” line.
If you’re using the actual-expense method for a home office, attach Form 8829 and carry the result to the designated Schedule C line. The simplified home office deduction goes directly on Schedule C without a separate form. The bottom of the form shows your net profit or loss, which flows to Form 1040 and feeds Schedule SE for self-employment tax.
One threshold matters at the start: an activity qualifies for Schedule C only if your primary purpose is earning income or profit and you engage in it with regularity. Hobbies and sporadic activities don’t qualify.14Internal Revenue Service. 2025 Instructions for Schedule C (Form 1040)
Records You Need to Keep
Every deduction rests on documentation. Keep receipts, bank statements, canceled checks, mileage logs, and electronic transaction records for every expense you claim. If the IRS asks about a deduction and you can’t produce records, the deduction is disallowed.
The general audit window is three years from the date you file. It extends to six years if you omit more than 25% of your gross income.15Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection There is no time limit at all for a fraudulent return or one that was never filed. Keeping records for at least seven years covers the six-year window with a margin.
What Happens If You Get It Wrong
Claiming deductions you’re not entitled to costs more than the tax itself. The standard accuracy-related penalty is 20% of the underpayment tied to a negligent or improper deduction. Gross valuation misstatements, such as significantly overstating the value of donated property, double the penalty to 40%.16Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments Fraudulent claims carry a 75% penalty on the underpayment and potential criminal prosecution. Interest runs on any unpaid balance from the original due date until you pay in full.