Finance Guide

Small Business Tax Deductions: What You Can Actually Write Off

The IRS allows small businesses to deduct "ordinary and necessary" business expenses. That's the standard. The problem is that most business owners either miss legitimate deductions because they don't know about them, or push deductions that don't meet the standard and end up in an audit. This guide covers what you can actually deduct, where the rules are tightest, and when to stop guessing and hire a CPA.

The top 12 deductions most small businesses miss

1. Business insurance premiums

General liability insurance, professional liability (errors and omissions), commercial auto, workers' comp, and business property insurance are all fully deductible. Many business owners pay these and never think to deduct them. Document each policy and premium amount.

2. Advertising and marketing expenses

Every dollar you spend on Google Ads, Facebook Ads, business cards, website hosting, SEO services, graphic design, print advertising, trade show booths, and promotional materials is deductible. This includes your monthly marketing agency fee, your email newsletter platform, and any software you use primarily for marketing.

3. Professional services

Fees paid to accountants, attorneys, bookkeepers, consultants, and business coaches are deductible as business expenses. Your CPA's fee for preparing your tax return is itself a deductible expense in the following year. Don't overlook this one — it's often several thousand dollars.

4. Business software and subscriptions

QuickBooks, Jobber, ServiceTitan, Calendly, Zoom, Microsoft 365, Adobe Creative Cloud, your CRM, your project management tool — anything you subscribe to for business purposes is deductible. If you use software partly for personal use (like a personal smartphone app that you also use for business), you can only deduct the business-use percentage.

5. Employee wages and contractor payments

Salaries and wages paid to employees are fully deductible, as are payments to independent contractors (1099 workers). If you pay a contractor more than $600 in a year, you're required to issue a 1099-NEC — make sure you're doing this, as the IRS cross-references it.

6. Retirement plan contributions

If you're self-employed or an S-corp owner, contributions you make to a SEP-IRA, SIMPLE IRA, or Solo 401(k) are deductible. This is one of the highest-leverage deductions available because it reduces your taxable income dollar-for-dollar while simultaneously building retirement savings. A solo 401(k) allows contributions up to $69,000 per year (2024 limit — verify current year) for owner-operators. Seriously underutilized.

7. Health insurance premiums

Self-employed business owners can deduct 100% of health insurance premiums for themselves, their spouse, and dependents — even if they don't itemize on their personal return. This is a significant deduction for owners paying their own premiums. Note: if you're eligible for coverage through a spouse's employer plan, this deduction is not available.

8. Meals (50% deductible)

Business meals — meals with clients, prospects, employees, or partners where you discuss business — are 50% deductible. The meal must be directly related to or associated with business. You need to document: who you ate with, what business was discussed, and the amount. A meal with a client where no business is discussed is not deductible. Keep receipts and write a brief note on the back about the purpose.

9. Business travel

Airfare, hotel, car rental, and 50% of meals while traveling for business purposes are deductible. The travel must be primarily for business — a two-day conference with one vacation day tacked on at the end is mostly deductible. A vacation with one business meeting is mostly not. Personal and business travel expenses must be separated if trips are mixed.

10. Education and training

Courses, certifications, books, and industry conferences that maintain or improve your skills in your current business are deductible. If you're a plumber taking a continuing education course on new code requirements, that's deductible. If you're a plumber taking a course to become a real estate agent, that's not — because it's education for a new career, not your current one.

11. Bank fees and interest

Monthly service fees on your business bank account, credit card processing fees (Stripe, Square, PayPal transaction percentages), and interest on business loans are all deductible. Keep personal and business accounts separate so these are easy to identify and document.

12. Tools, equipment, and supplies

Anything you purchase for use in your business — tools, equipment, office supplies, uniforms, safety gear — is deductible. For larger equipment purchases (over $2,500 typically), you may need to depreciate the cost over several years rather than deducting it all in one year. Section 179 allows you to deduct the full cost of qualifying equipment in the year of purchase up to the annual limit — ask your CPA if this applies to a major purchase.

Home office rules

The home office deduction is legitimate and frequently missed — but it's also one of the most audited deductions, so the rules matter.

To qualify, the space must be used regularly and exclusively for business. A guest bedroom with a desk in the corner that you use sometimes doesn't qualify. A room that is used only as your office — with no personal use — does qualify.

There are two calculation methods:

• Simplified method: $5 per square foot of your home office, up to 300 square feet maximum. Maximum deduction: $1,500. No depreciation recapture, less record-keeping.
• Regular method: Calculate the percentage of your home used for business (office square footage ÷ total home square footage) and apply that percentage to your actual home expenses — mortgage interest or rent, utilities, insurance, repairs. More complex, but often results in a larger deduction for owners with higher housing costs.

Renters can use the regular method. Homeowners who use the regular method must handle depreciation recapture when they sell the home, which adds complexity. Your CPA can calculate which method works better for your situation.

Vehicle rules

If you use a vehicle for business, you can deduct the business-use portion. Two methods:

• Standard mileage rate: The IRS sets a per-mile rate each year (67 cents per mile in 2024 — verify current rate). Track your business miles and multiply. You cannot use this method if you've previously claimed depreciation on the vehicle.
• Actual expense method: Track your total vehicle expenses (gas, insurance, maintenance, depreciation) and deduct the percentage used for business. If you drive the vehicle 80% for business, you deduct 80% of total expenses.

You need a mileage log either way — date, destination, business purpose, and miles for each trip. A mileage tracking app (MileIQ, Everlance) makes this painless. A claimed deduction without documentation is an audit risk.

What NOT to deduct

• Personal expenses labeled as business. Your personal cell phone plan isn't fully deductible — only the business-use percentage is. Buying a new TV and calling it a "client entertainment display" doesn't work.
• Fines and penalties. Traffic tickets, IRS penalties, and regulatory fines are not deductible as business expenses, even if you incurred them while doing business.
• Political contributions and lobbying. Donations to political candidates or PACs are not deductible as business expenses.
• Capital expenses classified as operating expenses. If you buy a piece of equipment that will last more than a year, it's typically a capital expense that must be depreciated — not a same-year deduction. Misclassifying capital expenses is a common audit trigger.

When to get a CPA

If any of these are true, you need a CPA — not just a tax software subscription:

• Your gross revenue exceeds $100,000 per year
• You have employees (payroll tax is complex and the penalties for getting it wrong are severe)
• You're structured as an S-Corp (owner salary vs. distributions requires careful management)
• You're buying or selling a business
• You received an IRS notice
• You have significant equipment purchases or real estate
• You're not sure what's deductible

A good CPA for a small business typically costs $1,000–$3,000 per year for tax preparation plus quarterly planning. If they're finding $10,000–$20,000 in additional deductions you'd have missed, that's an obvious ROI. If you're spending $800 on TurboTax and leaving that money on the table, that's a false economy.