Writing off taxes means claiming deductions that reduce your taxable income, which lowers the amount you owe. The term “write-off” is informal shorthand for a tax deduction: an expense the IRS lets you subtract from your income before calculating your tax bill. Whether you’re an employee or self-employed, understanding which expenses qualify and how to claim them can save you hundreds or thousands of dollars each year.
What a Tax Write-Off Actually Does
A write-off reduces your taxable income, not your tax bill dollar for dollar. If you’re in the 22% tax bracket and you write off $1,000 in qualifying expenses, you save $220 in taxes, not $1,000. This distinction matters because people sometimes confuse deductions with tax credits. A tax credit directly reduces the amount of tax you owe. A $1,000 credit saves you exactly $1,000. Some credits are even refundable, meaning if the credit exceeds what you owe, the IRS sends you the difference.
Write-offs and deductions are the same thing. You’ll hear both terms used interchangeably, and they work identically on your return.
Standard Deduction vs. Itemizing
Every taxpayer gets a choice: take the standard deduction or itemize individual expenses. You can’t do both. The standard deduction for 2026 is $16,100 for single filers, $32,200 for married couples filing jointly, and $24,150 for heads of household. If your total itemizable expenses fall below those thresholds, the standard deduction saves you more money and requires far less paperwork.
Roughly 90% of taxpayers take the standard deduction because it’s simpler and often larger than their combined itemized expenses. But if you have a mortgage, make significant charitable donations, or pay high state and local taxes, itemizing may put you ahead. The only way to know is to add up your qualifying expenses and compare.
Common Itemized Deductions
If you choose to itemize, the IRS allows deductions for several categories of personal spending:
- Mortgage interest: Interest paid on a home loan is one of the largest itemized deductions for homeowners.
- State and local taxes (SALT): Income taxes, sales taxes, real estate taxes, and personal property taxes, capped at $10,000 combined for most filers.
- Charitable donations: Cash and non-cash contributions to qualifying organizations. Keep receipts and written acknowledgment for donations of $250 or more.
- Medical and dental expenses: Costs for yourself, your spouse, and dependents, but only the portion that exceeds 7.5% of your adjusted gross income. If your AGI is $60,000, you can only deduct medical expenses above $4,500.
- Casualty and theft losses: Losses from federally declared disasters.
- Capital losses: Investment losses can offset gains and up to $3,000 of ordinary income per year.
You report itemized deductions on Schedule A of your tax return. If the total exceeds your standard deduction, itemizing wins.
Write-Offs for Self-Employed Workers
Self-employed individuals, freelancers, and small business owners have access to a much broader set of write-offs. These go on Schedule C and reduce your business income before you calculate both income tax and self-employment tax (the 15.3% you pay to cover Social Security and Medicare). You can claim these business deductions even if you also take the standard deduction on your personal return, because they’re calculated separately.
Here are the categories that matter most:
- Home office: If you use part of your home regularly and exclusively for business, you can deduct a proportional share of rent or mortgage interest, utilities, insurance, and property taxes. The simplified method lets you deduct $5 per square foot of office space, up to 300 square feet.
- Vehicle expenses: Business-related driving can be deducted using either your actual costs (gas, insurance, repairs) or the IRS standard mileage rate, which is 70 cents per mile for 2025. You need a log showing the date, destination, business purpose, and miles driven for each trip.
- Health insurance premiums: If you’re self-employed and not eligible for coverage through a spouse’s employer plan, you can deduct premiums for yourself, your spouse, and your dependents.
- Software and equipment: Computers, phones, subscriptions, and cloud services used for business are deductible. Larger purchases like equipment can often be deducted in full the year you buy them rather than depreciated over time.
- Business travel: Airfare, hotels, rental cars, and public transportation for business trips. Meals during business travel or with clients are 50% deductible.
- Advertising and marketing: Online ads, social media promotions, business cards, and website costs including hosting, domain registration, and design.
- Professional services: Fees paid to accountants, attorneys, bookkeepers, and other professionals who help you run your business.
- Contractor payments: Amounts paid to independent contractors for business work. If you pay someone more than $600 in a year, you’ll need to issue them a 1099 form.
- Office supplies: Paper, ink, postage, furniture, and other everyday business supplies.
- Licenses, permits, and insurance: Business licenses, professional certifications, and liability or professional insurance premiums.
- Education and training: Classes, workshops, conferences, and books that maintain or improve skills related to your current business.
- Bank and processing fees: Monthly account fees, credit card processing charges, and payment platform fees.
- Half of self-employment tax: You pay 15.3% in self-employment tax, and the IRS lets you deduct 7.65% (the employer-equivalent portion) as an adjustment to income.
The key rule for all business write-offs: the expense must be “ordinary and necessary” for your line of work. An ordinary expense is one that’s common in your industry. A necessary expense is one that’s helpful and appropriate for running your business. A graphic designer can write off Adobe software. A plumber probably can’t.
Above-the-Line Deductions Anyone Can Take
Some deductions reduce your income before you even decide between the standard deduction and itemizing. These “above-the-line” deductions (officially called adjustments to income) are available whether you itemize or not:
- Student loan interest: Up to $2,500 of interest paid on qualified student loans, subject to income limits.
- IRA contributions: Contributions to a traditional IRA may be deductible depending on your income and whether you have a retirement plan at work.
- HSA contributions: Money deposited into a Health Savings Account if you have a qualifying high-deductible health plan.
- Educator expenses: Teachers can deduct up to $300 in unreimbursed classroom supplies.
These deductions lower your adjusted gross income, which can also help you qualify for other tax breaks that have AGI-based thresholds.
How to Keep Records That Hold Up
Claiming write-offs without proper documentation is how people get into trouble during audits. The IRS requires supporting documents for every deduction: receipts, invoices, bank statements, canceled checks, or credit card statements. Each record should show who was paid, how much, the date, and what the payment was for.
For travel, transportation, and meal expenses, the requirements are stricter. You need to document the business purpose of the expense, who you met with (for meals), and the business relationship. A credit card statement alone isn’t enough for these categories. Keep a contemporaneous log, meaning you record the details at or near the time the expense occurs, not months later when you’re scrambling at tax time.
For assets like equipment or vehicles, maintain records showing when you bought the item, what you paid, how you use it for business, and any depreciation you’ve claimed. If you sell the asset later, you’ll need records of the sale price and any associated costs.
The IRS says you can use any recordkeeping system that clearly shows your income and expenses. A spreadsheet, an accounting app, or a shoebox of organized receipts all work, as long as the information is complete and accessible. Digital copies of receipts are accepted, so scanning or photographing paper receipts is a practical way to avoid losing them. Keep tax records for at least three years after you file, or seven years if you claim a loss from bad debt or worthless securities.
Deciding Which Write-Offs to Claim
Start by separating business expenses from personal deductions. If you’re self-employed, list every business expense you’ve paid during the year and categorize them using the Schedule C categories. These reduce your business income regardless of whether you itemize.
Next, add up your potential itemized deductions: mortgage interest, state and local taxes, charitable contributions, and qualifying medical expenses. Compare that total to the standard deduction for your filing status. If itemizing wins, claim those deductions on Schedule A. If it doesn’t, take the standard deduction and move on.
Don’t forget the above-the-line deductions. Student loan interest, HSA contributions, and IRA contributions reduce your taxable income on top of either the standard deduction or itemized deductions. These are easy to overlook but can meaningfully lower your bill. Tax software will walk you through each category and flag deductions you might qualify for, which makes the process considerably easier than working through paper forms manually.