The deductions service business owners miss most often aren’t complicated or obscure. They’re everyday costs that slip through because nobody tracked them properly or the owner didn’t realize they counted.

The home office deduction applies if you work from a dedicated space in your home. You can deduct a portion of your rent or mortgage interest, utilities, insurance, and repairs. The simplified method gives you $5 per square foot up to 300 square feet. The actual expense method requires more documentation but can yield a larger deduction if your home office is substantial. The key word is dedicated. The space has to be used regularly and exclusively for business.

Vehicle and mileage is one of the biggest missed deductions for service businesses. For 2026, the standard mileage rate is 72.5 cents per mile. If you drive 15,000 business miles in a year, that’s nearly $11,000 in deductions. But you need a log. Without documentation of business versus personal miles, you lose the deduction or face problems if audited. Many owners skip tracking and leave thousands on the table.

Equipment like tools, computers, vehicles, and machinery can often be written off immediately using Section 179 or bonus depreciation instead of spreading the deduction over several years. The rules have limits and change periodically, but many service businesses can deduct the full cost of equipment purchases in the year they buy them. This applies to everything from laptops to work trucks to specialized tools for your trade.

Retirement plan contributions are deductible if you’re self-employed. Contributions to a SEP-IRA, SIMPLE IRA, or solo 401(k) reduce your taxable income and build retirement savings at the same time. A SEP-IRA lets you contribute up to 25% of net self-employment income. Many owners don’t realize how much they can set aside or that it directly lowers their tax bill.

Self-employed health insurance premiums are deductible if you pay for your own coverage and aren’t eligible through a spouse’s employer. This includes medical, dental, and qualifying long-term care insurance for you, your spouse, and dependents. This deduction goes on your personal return, and many owners miss it entirely.

Software and subscriptions add up over a year. QuickBooks, project management tools, scheduling software, design programs, cloud storage, and industry-specific subscriptions are all deductible. Many owners forget to track them because they hit a personal card or get lost in the shuffle of small monthly charges. The same goes for your phone and internet if you use them for business. You can deduct the percentage that’s genuinely business use, but you have to track and document it.

The common thread is tracking. Most of these deductions require documentation throughout the year. If you wait until April to pull this together, you’ll miss things. You won’t remember that $400 in small tool purchases, the mileage to client sites, or the software subscriptions that renewed automatically.

This is why bookkeeping and tax services work best when they’re connected. Clean books through the year capture these costs as they happen, and the tax side knows what’s available when it’s time to file.

What applies to your business depends on your situation. Not everyone has a home office. Not everyone drives for work. Retirement contributions depend on your income and cash flow. A tax strategy conversation with someone who knows your numbers can identify which deductions apply and make sure you’re set up to capture them. If you’re not sure what you’re missing, reach out for a consultation.