The Most Common Small Business Tax Deductions and How to Document Them
Every deduction you miss is profit you hand to the tax office, and every deduction you cannot prove is one you may have to give back. This checklist covers the deductions most small businesses can claim, the rules that trip people up and the specific records that make each one stick.
Key takeaways
- A business expense is deductible when it is ordinary in your trade and necessary for your work. That is the whole test, and it covers more than most owners claim.
- The deductions owners most often miss are the home office, vehicle mileage, software subscriptions, bank fees and half of self-employment tax.
- For every deduction, keep proof of three things: what you paid, when you paid it and why it was for the business.
- This article uses US federal rules as examples. Limits and rates change each year and other countries have their own lists, so verify before filing.
The US tax code allows a business to deduct any expense that is "ordinary and necessary." Ordinary means common and accepted in your line of work. Necessary means helpful and appropriate, not indispensable. A photographer's camera, a consultant's laptop and a bakery's flour all pass easily. So do dozens of smaller items that owners forget about because they feel too minor to matter.
They matter. Imagine a sole proprietor in the 22% federal bracket who also pays 15.3% self-employment tax. Each $1,000 of legitimate deductions they fail to claim costs them roughly $300 to $350 in extra tax, more once state tax is added. Over a year of missed subscriptions, mileage and home office costs, that adds up to real money.
The documentation rule that covers everything
Before the list, one principle. For any deduction, the IRS wants to see what the expense was, how much it cost, when it happened and how it related to the business. A bank statement proves the first three. A receipt or invoice adds the detail. A short note adds the business purpose. Build the habit of capturing all three at the time of the expense.
How long to keep records: the IRS generally says three years from the filing date, six years if you underreported income by more than 25%, and seven years for bad debt deductions. Employment tax records should be kept for at least four years. Keep records for assets you depreciate until several years after you dispose of them.
Common mistake
Relying on a credit card statement alone. A statement line reading "AMZN Mktp $212.40" proves you paid Amazon, not what you bought or that it was for the business. For purchases that mix personal and business items, keep the itemized receipt and mark which lines you are claiming.
The deductions checklist
1. Home office
If you use part of your home regularly and exclusively for business, and it is your principal place of business, you can deduct a share of your housing costs. There are two methods. The simplified method allows $5 per square foot up to 300 square feet, a maximum of $1,500, with no receipts beyond the measurement. The regular method deducts the business-use percentage of actual costs: rent or mortgage interest, utilities, insurance, repairs and depreciation.
Documentation: a floor plan or measurement showing the office area and total home area, photos of the space, and for the regular method, every utility bill and housing cost for the year.
2. Vehicle expenses
You can deduct business driving by the standard mileage rate or by actual costs. The IRS sets the mileage rate each year; for 2025 it was 70 cents per business mile, and it changes annually, so check the current figure. Actual costs include fuel, insurance, repairs, registration and depreciation, multiplied by the business-use percentage. Commuting from home to a regular workplace is never deductible, but trips between work locations, to clients and to suppliers are.
Documentation: a contemporaneous mileage log with the date, destination, purpose and miles for each trip. A mileage tracking app that records trips automatically is the easiest way to meet this standard. For actual costs, keep all vehicle receipts and your odometer readings at the start and end of the year.
3. Equipment and depreciation
Computers, machinery, furniture and vehicles are capital assets. You either depreciate them over several years or, in the US, elect to expense them immediately under Section 179 up to an annual limit that is currently well above $1 million, or use bonus depreciation. Items that cost less than a de minimis threshold (commonly $2,500 per item for businesses without audited financial statements) can simply be expensed.
Documentation: the purchase invoice, the date placed in service and a note on business-use percentage if the asset is also used personally.
4. Software, subscriptions and online services
Accounting software, design tools, cloud storage, website hosting, domain names, email marketing platforms, project management apps and paid AI tools are all deductible when used for the business.
Documentation: the email receipt or invoice for each billing cycle. Export a year-end billing history from each vendor and file it.
5. Phone and internet
If you use one phone and one internet connection for both business and personal life, deduct the business-use percentage. A second line used only for business is fully deductible.
Documentation: monthly bills and a reasonable, written estimate of business use, such as a sample week of call and data usage.
6. Business meals
Meals with clients, prospects or business contacts where business is discussed are generally 50% deductible in the US. Meals while traveling for business are also 50% deductible. Entertainment, such as event tickets or golf, is not deductible at the federal level.
Documentation: the itemized receipt plus a note of who attended and what business was discussed. Write it on the receipt or in your expense app before you leave the restaurant.
7. Travel
Airfare, hotels, rental cars, taxis, baggage fees and tips on a trip that is primarily for business are deductible. If you add personal days, deduct only the business portion of lodging and the full fare only if the trip was mainly business.
Documentation: booking confirmations, hotel folios, and a copy of the itinerary or meeting calendar showing the business purpose of each day.
8. Advertising and marketing
Online ads, printed materials, website design, sponsorships, business cards, promotional items and the cost of running a giveaway are deductible.
Documentation: invoices and ad platform billing reports.
9. Professional services
Fees paid to accountants, lawyers, consultants and bookkeepers for business matters are deductible. The portion of a tax preparer's fee that relates to your business schedules counts, while the part for your personal return does not.
Documentation: engagement letters and invoices. Ask your preparer to split the fee between business and personal work on the invoice.
10. Contractor payments
Payments to freelancers and independent contractors are deductible. In the US, if you pay an unincorporated contractor $600 or more in a year for services, you generally must file Form 1099-NEC. Note that this reporting threshold is scheduled to change under recent legislation, so check the current amount.
Documentation: a signed Form W-9 from each contractor before you pay them, invoices for the work and copies of the 1099s you file.
11. Wages and benefits
Employee salaries, the employer share of payroll taxes, health insurance contributions, retirement plan contributions and most fringe benefits are deductible.
Documentation: payroll reports, filed payroll tax returns and plan statements.
12. Insurance
General liability, professional liability, property, workers' compensation and business interruption premiums are deductible. Self-employed owners can often deduct health insurance premiums for themselves and their family as an adjustment to income, provided they are not eligible for an employer plan.
Documentation: policy declarations and premium invoices.
13. Rent and utilities
Rent for an office, shop, warehouse or coworking desk is deductible, along with utilities for those spaces.
Documentation: the lease agreement and monthly payment records.
14. Bank fees, interest and payment processing
Monthly account fees, wire fees, credit card processing fees and interest on business loans or business credit cards are deductible. Interest on a personal credit card used for a business purchase is deductible for that purchase, but tracking it is painful, which is one reason to use a separate business card.
Documentation: bank and processor statements, loan agreements and year-end interest summaries.
15. Education and training
Courses, books, conferences and certifications that maintain or improve skills in your current business are deductible. Education that qualifies you for a new trade or business is not.
Documentation: receipts plus a brief note linking the course to your existing work.
16. Startup and organizational costs
In the US you can deduct up to $5,000 of startup costs and $5,000 of organizational costs in the first year, with the rest amortized over 15 years. Both $5,000 amounts phase out once total costs exceed $50,000.
Documentation: receipts for market research, legal formation fees, pre-opening advertising and similar costs, with dates showing they came before the business opened.
17. Half of self-employment tax and retirement contributions
Sole proprietors and partners can deduct half of their self-employment tax when calculating adjusted gross income. Contributions to a SEP-IRA, SIMPLE IRA or solo 401(k) are also deductible up to annual limits that change each year.
Documentation: the calculation on your return and plan contribution confirmations.
A simple documentation system
- Use one business bank account and one business card. This alone eliminates most sorting problems and gives you a clean statement trail.
- Capture receipts on the spot. Photograph each receipt with your accounting app or a receipt scanner. Add a one-line note of purpose for anything that is not obvious.
- Categorize weekly. Spend ten minutes each week assigning transactions to the categories above. Flag anything you are unsure about for your accountant.
- Keep a mileage log that runs automatically. Turn on trip detection and classify trips at the end of each day.
- Store everything in one cloud folder by year. Receipts, invoices, bank statements, payroll reports and the filed return go in the same place.
- Reconcile at year end. Before filing, compare total deductions by category against last year and investigate any big jump or drop. Mistakes show up as anomalies.
Worked example
Imagine a consultant with $120,000 in revenue who claims only the obvious costs: $6,000 in software and $4,000 in professional fees. Now suppose they add a home office under the simplified method ($1,500), 6,000 business miles at the 2025 rate ($4,200), the business share of phone and internet ($1,200), client meals at 50% ($900) and a conference trip ($2,400). That is $10,200 of additional deductions. At a combined marginal rate of roughly 35% for federal income and self-employment tax, the extra deductions save about $3,570, before any state tax saving. The records needed to support them fit in a single folder.
Pro tip
When you are unsure whether an expense is deductible, record it anyway and tag it "ask accountant." It is far easier to drop a questionable item at filing time than to recover a legitimate one you never tracked.
Usually deductible
- Costs that directly produce revenue or keep the business running
- The business share of mixed-use items like a phone or car
- Fees, interest and taxes paid to operate the business
Usually not deductible
- Commuting, personal clothing that could be worn outside work, and entertainment
- Fines, penalties and political contributions
- Federal income tax itself and most personal living costs
Outside the United States
The "wholly and exclusively" test in the UK, the deductibility rules in Canada and Australia, and the input VAT rules in the EU all follow the same spirit: business costs reduce taxable business profit, and you need proof. The specific limits, such as home office methods, mileage rates and meal percentages, differ by country and change often. Check your national tax authority's guidance or ask a local accountant before applying the US figures above.
Year-end deduction checklist
- Home office measured and method chosen
- Mileage log complete for the year with purpose noted on each trip
- All software and subscription invoices exported and filed
- Meal receipts annotated with attendees and purpose
- W-9s collected and 1099s prepared for contractors over the threshold
- Equipment purchases listed with dates placed in service
- Retirement contributions made before the deadline for your plan type
- Uncertain items flagged for your accountant
Frequently asked questions
Can I deduct clothing I wear for work?
Only if it is not suitable for everyday wear, such as a uniform with a logo, safety gear or costumes. A suit you wear to client meetings is not deductible even if you only bought it for work.
Do I need receipts for small expenses?
The IRS does not require receipts for most expenses under $75, but you still need a record of the amount, date and purpose. Since photographing a receipt takes seconds, keeping them all is the safer habit.
Can I deduct expenses paid from my personal account?
Yes, if they were genuinely for the business. Record them as an owner contribution in your books and keep the receipt. Doing this often, however, weakens the separation between you and the business, which matters for liability as well as taxes.
What if the business made a loss?
For most structures, a business loss can offset other income in the same year, subject to rules on passive activity and excess business losses. Losses that cannot be used may carry forward. Keep full records of loss years, since they can reduce tax in future profitable years.
Related reading
The bottom line
Most small businesses underclaim deductions not because the rules are strict but because the records are missing. Work through the checklist above once, set up a system that captures receipts and mileage as they happen, and review the categories each year. The tax you save will usually dwarf the time it takes. Limits, rates and thresholds change annually and vary by country, so confirm the current figures with an accountant or your tax authority before you file.
