As a 1099 contractor, you can write off any expense that is ordinary and necessary for your line of work, and those deductions directly reduce the income subject to the 15.3 percent self-employment tax you owe on top of regular income tax.1Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes) The list is long: home office costs, vehicle mileage, equipment, software, phone and internet, health insurance premiums, retirement contributions, professional fees, and continuing education. Several of the most valuable write-offs sit outside Schedule C entirely, and they are the ones contractors most often miss.
The Ordinary and Necessary Test
Every business deduction runs through the same two-part test. An expense must be ordinary, meaning common and accepted in your industry, and necessary, meaning helpful and appropriate for your work. It does not have to be essential. A graphic designer buying illustration software passes both tests easily. A boat almost certainly does not.
When an expense has a personal component, only the business-use portion is deductible. A phone you use 60 percent for work gets a 60 percent deduction on the bill. Clean records of that split are the difference between a deduction that holds up and one the IRS disallows.
Home Office
If you work from home, you can deduct a share of your housing costs, but only for space used exclusively and regularly for business. A spare bedroom that also serves as a guest room does not qualify. A dedicated desk area in a finished basement does. You choose one of two calculation methods each year.
The simplified method gives you $5 per square foot of office space, capped at 300 square feet, for a maximum deduction of $1,500.2Internal Revenue Service. Simplified Option for Home Office Deduction No individual bills to track. It also lets you claim your full mortgage interest and property tax deductions separately on Schedule A, which the regular method does not.
The regular method uses actual costs: rent or mortgage interest, utilities, insurance, and repairs, multiplied by your office’s share of total square footage. If the office takes up 15 percent of your home, you deduct 15 percent of those shared costs. Expenses that benefit only the office, like repainting that room, are fully deductible. The regular method often produces a bigger number, but it requires careful record-keeping and can involve depreciation on the home itself.3Internal Revenue Service. FAQs – Simplified Method for Home Office Deduction
Vehicle and Travel
Driving between job sites, to client meetings, or to pick up supplies counts as deductible business travel. Commuting from home to a regular workplace does not. If your home is your principal place of business, though, the first trip out to a client each day is a business trip, not a commute.
You pick one method for the entire tax year. The standard mileage rate for 2026 is 72.5 cents per mile, which bundles fuel, maintenance, insurance, and depreciation into a single per-mile figure.4Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents Per Mile, Up 2.5 Cents The actual expense method tracks every dollar spent on gas, oil changes, tires, repairs, insurance, registration, and depreciation, then applies your business-use percentage. Actual expenses sometimes yield a bigger deduction for expensive or fuel-hungry vehicles, but the record-keeping is heavier. Either method requires a contemporaneous mileage log with date, destination, purpose, and miles for every trip.
Longer trips open up more deductions. Airfare, hotels, rental cars, parking, and tolls are all deductible when the travel is for business. Business meals eaten while traveling away from your tax home are deductible at 50 percent, as long as they are not lavish or extravagant.5Internal Revenue Service. Heres What Businesses Need to Know About the Enhanced Business Meal Deduction Tips and taxes on the meal are included in the 50 percent calculation.
Equipment, Software, and Supplies
Computers, printers, cameras, specialized trade tools, and office furniture are all deductible when used for your work. So are software subscriptions for accounting, design, project management, and similar business functions.
Items expected to last more than a year are normally depreciated over their useful life, but Section 179 lets you deduct the full cost in the year of purchase. For 2026, you can expense up to $2,560,000 of qualifying equipment, with the deduction beginning to phase out once total equipment purchases exceed $4,090,000.6Internal Revenue Service. Revenue Procedure 2025-32 Most contractors will never approach those ceilings, which means the full cost of a new laptop or work truck can come off in the year you buy it.
Everyday supplies, from paper and ink to postage and packing materials, are deducted in the year you buy them. Keep digital copies of receipts. The IRS can ask you to prove the business purpose of any purchase.
Professional Fees, Communication, and Education
Fees paid to other professionals to support your business are fully deductible. That covers accounting and tax preparation, legal fees for contract review, and payments to marketing agencies or advertising platforms. Business insurance premiums, whether general liability, professional liability, or errors-and-omissions coverage, also qualify.
Communication costs get split between business and personal use. If your cell phone is 60 percent business, 60 percent of the bill is deductible. Same logic for internet service. A separate business phone line is fully deductible. Trade association dues and subscriptions to industry publications belong in this category too.
Training and education are deductible when they maintain or improve skills you already use in your current work.7Internal Revenue Service. Topic No. 513, Work-Related Education Expenses Workshops, online courses, certification renewals, conferences, and the books and materials that go with them all count. The line to watch: education that qualifies you for an entirely new career is not deductible, even if it feels related. A web developer taking an advanced JavaScript course qualifies. The same developer going to law school does not.
Self-Employed Health Insurance
If you are not eligible for a health plan through a spouse’s employer or another job, you can deduct premiums paid for medical, dental, and vision coverage for yourself, your spouse, your dependents, and your children under age 27, even if those children are not your dependents for other tax purposes.8Internal Revenue Service. Topic No. 502, Medical and Dental Expenses Premiums on a qualifying long-term care policy count as well.
This one is an adjustment to gross income on Schedule 1, not a business expense on Schedule C. That distinction matters. It lowers your adjusted gross income, which can help you qualify for other tax breaks that phase out at higher income levels. The deduction cannot exceed your net self-employment profit for the year. Anything left over can go with your itemized medical expenses on Schedule A if the total clears the 7.5 percent of income threshold.
Retirement Contributions
Retirement contributions are among the largest write-offs available to a 1099 contractor, cutting your taxable income now while building long-term savings. Two plans dominate the self-employed world.
A SEP IRA lets you contribute up to 25 percent of your net self-employment earnings, capped at $69,000 for 2026. Setup is simple, and annual filing requirements do not kick in until balances reach a certain level. The trade-off is that all contributions come from the employer side; there are no elective deferrals.9Internal Revenue Service. SEP Contribution Limits (Including Grandfathered SARSEPs)
A Solo 401(k) has you wearing both hats. On the employee side, you can defer up to $24,500 in 2026, or $32,500 if you are 50 or older, and up to $35,750 if you are 60 through 63. On top of that, employer profit-sharing contributions of up to 25 percent of net earnings are allowed, with a combined cap of $72,000, or $80,000 if you are 50 or older. The Solo 401(k) also offers a Roth option, letting you contribute after-tax dollars that grow tax-free.10Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
Both plans deliver an adjustment to income rather than a Schedule C expense. Contributions must land by your tax filing deadline, including extensions, to count for the current tax year.
Half of Your Self-Employment Tax
As a 1099 contractor, you pay the full 15.3 percent self-employment tax: 12.4 percent for Social Security on net earnings up to $184,500 in 2026, and 2.9 percent for Medicare on all net earnings.11Social Security Administration. If You Are Self-Employed Because employees and employers normally split those taxes, the IRS lets you deduct the employer-equivalent half as an adjustment to gross income.12Internal Revenue Service. Topic No. 554, Self-Employment Tax
The math runs through Schedule SE and flows to Schedule 1 of your Form 1040. You do not need to itemize. On $100,000 of net self-employment income and roughly $14,130 of self-employment tax, you deduct about $7,065 from gross income, lowering what is subject to regular income tax. Many contractors overlook this because it never appears on Schedule C, but it is automatic once Schedule SE is complete.
The 20 Percent Qualified Business Income Deduction
The Section 199A deduction, usually called the QBI deduction, lets eligible contractors deduct up to 20 percent of their qualified business income from taxable income.13Internal Revenue Service. Qualified Business Income Deduction It was set to expire after 2025, but the One Big Beautiful Bill Act, signed in July 2025, made it permanent.
Sole proprietors, partners, and S corporation shareholders can take it. W-2 income and C corporation income do not qualify. For contractors in specified service fields such as law, accounting, health care, and consulting, the deduction phases out at higher income levels. For 2026, those phase-out ranges run roughly $200,000 to $275,000 for single filers and $400,000 to $550,000 for joint filers. Below those thresholds, most contractors take the full 20 percent without additional limits.
QBI is claimed on your personal return and reduces income tax only, not self-employment tax. Even so, a 20 percent cut to taxable business income is substantial, and eligibility is worth confirming every year.
Hobby or Business
The IRS can reclassify your work as a hobby, and if that happens, your business deductions disappear. To protect them, you need to show a genuine intent to earn a profit. The agency weighs several factors: whether you keep accurate books, operate in a businesslike manner, depend on the income, and have a history of profit.14Internal Revenue Service. Know the Difference Between a Hobby and a Business
No single factor decides it. An activity that loses money for several years can still be a business if you are making real changes to improve profitability. An activity that turns an occasional profit can still be a hobby if you treat it casually and it has strong recreational appeal. The practical protection is straightforward: thorough financial records, a separate business bank account, active marketing, and documentation of the steps you take to grow or sustain income.
Where the Deductions Go on Your Return
You report business income and most deductions on Schedule C (Form 1040), titled “Profit or Loss From Business.”15Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss From Business (Sole Proprietorship) The form asks for your name, Social Security number or EIN, a business activity code, and then walks through specific expense lines for office expenses, travel, depreciation, advertising, insurance, and more. Totals flow to your Form 1040 to determine taxable income.
Before you start, pull together receipts, mileage logs, utility bills, insurance statements, and bank or credit card records for the full calendar year. Sorting them by expense category before you file saves real time. Remember that several of the biggest write-offs, retirement contributions, self-employed health insurance, and half your self-employment tax, are reported on Schedule 1 rather than Schedule C. They still reduce taxable income, but they live in a different place on your return.