Small Business Tax Deductions: The Complete 2025-2026 Guide

The One Big Beautiful Bill Act changed the math on small business deductions. Signed July 4, 2025, OBBBA restored 100% bonus depreciation, raised the Section 179 limit to $2.5 million, and increased the QBI deduction from 20% to 23% starting in 2026. If you’re filing your 2025 return right now or planning for 2026, the deductions available to you are significantly more generous than they were two years ago.

This guide covers 25+ small business tax deductions organized by category, updated for both the 2025 tax year (which you’re filing now) and the 2026 changes already in effect. We’ve also included entity-specific guidance because what you can deduct depends on whether you’re a sole proprietor, S-Corp owner, or partner in a partnership.

What are small business tax deductions?

Small business tax deductions are eligible expenses that reduce your taxable business income, lowering the amount of federal income tax and self-employment tax you owe. Common deductions include home office expenses, vehicle mileage ($0.70/mile in 2025), health insurance premiums, retirement contributions, and equipment purchases. The One Big Beautiful Bill Act (signed July 2025) made the QBI deduction permanent and increased it to 23% for 2026, while restoring 100% bonus depreciation. Most deductions are reported on Schedule C (sole proprietors), Form 1065 (partnerships), or Form 1120-S (S-Corps).

Key Takeaways

• OBBBA expanded multiple deductions — QBI made permanent (23% starting 2026), Section 179 raised to $2.5M, 100% bonus depreciation restored for property placed in service after January 19, 2025
• Entity type determines which deductions apply — Schedule C, S-Corp, and partnership owners have different rules for health insurance, retirement contributions, and self-employment tax
• Section 179 lets you deduct equipment immediately — Up to $2.5 million in qualifying equipment and vehicles (including SUVs over 6,000 lbs GVWR) in the year purchased
• Home office deduction has two methods — Simplified ($5/sq ft, max $1,500) or actual expenses (percentage of rent/mortgage, utilities, insurance)
• Self-employed health insurance is 100% deductible — Premiums for you, spouse, and dependents reduce your adjusted gross income
• Retirement contributions are often the largest single deduction — Solo 401(k) allows up to $70,000 in combined contributions for 2025 ($81,250 if you’re age 60-63)

What Changed: OBBBA Tax Deduction Updates

The One Big Beautiful Bill Act (P.L. 119-21) signed July 4, 2025 made several changes that directly affect how much small business owners can deduct. Here’s what moved:

QBI deduction made permanent and increased. The 20% qualified business income deduction under Section 199A was set to expire December 31, 2025. OBBBA made it permanent and increased the rate to 23% for tax years beginning after December 31, 2025. That means your 2025 return still uses 20%, but your 2026 return gets the higher rate. OBBBA also introduced a $400 minimum deduction for anyone with at least $1,000 in qualified business income and expanded the phase-in range to $75,000 (single) / $150,000 (joint). See our QBI deduction guide for the full breakdown, or run the numbers with our QBI calculator.

100% bonus depreciation restored permanently. Before OBBBA, bonus depreciation was phasing down — 80% in 2023, 60% in 2024, and headed to 40% in 2025. OBBBA restored it to 100% for qualifying property placed in service after January 19, 2025. This is permanent. No more phase-down.

Section 179 raised to $2.5 million. The expensing limit jumped to $2.5 million with a $4 million phaseout threshold, both indexed for inflation going forward. For 2026, the inflation-adjusted limit is approximately $2.56 million. Full details in our Section 179 deduction guide.

R&D expenses immediately deductible again. Since 2022, businesses had to capitalize and amortize domestic research expenses over 5 years. OBBBA reversed this — domestic R&E expenditures paid or incurred after December 31, 2024 are immediately deductible. If you’re a tech company or manufacturer, this is significant.

Business interest deduction improved. The Section 163(j) limitation reverts from an EBIT-based calculation to EBITDA-based, which is more generous for capital-intensive businesses.

For the full picture of how OBBBA affects Texas businesses specifically, see our OBBBA tax guide.

Operating Expense Deductions

Ordinary and necessary business expenses are deductible in the year you pay them (cash basis) or incur them (accrual basis). These are the expenses most small business owners already track:

• Rent and office space — Monthly rent, coworking memberships, storage facilities used for business
• Utilities — Internet, phone, electricity for your business space (business-use portion only if home-based)
• Office supplies and software — Everything from printer paper to your QuickBooks subscription, project management tools, and cloud storage
• Professional services — Accounting fees, legal fees, consulting. (Wondering what CPA services typically cost? See our guide on how much a CPA costs.)
• Business insurance — General liability, professional liability (E&O), workers’ comp, commercial auto. Health insurance is covered separately below.
• Bank fees and payment processing — Business account maintenance fees, credit card processing charges, merchant services
• Advertising and marketing — Google Ads, social media advertising, website hosting, business cards, signage, trade show booths
• Education and training — Courses, certifications, conferences, and seminars that maintain or improve skills in your current business

The key test: the expense must be ordinary (common in your industry) and necessary (helpful and appropriate for your business). The IRS doesn’t require that an expense be indispensable — just that it has a clear business purpose.

Home Office Deduction

You can deduct expenses for the portion of your home used regularly and exclusively for business. The IRS offers two methods:

Simplified method: $5 per square foot of your dedicated office space, up to 300 square feet. Maximum deduction: $1,500. No depreciation calculation, no tracking individual expenses. Quick and straightforward.

Actual expense method: Calculate the percentage of your home used for business (usually square footage of office divided by total square footage), then apply that percentage to your mortgage interest or rent, property taxes, utilities, insurance, repairs, and depreciation. This method often produces a larger deduction but requires more record-keeping.

Which should you choose? Run the math both ways. A 200-square-foot office in a $2,400/month apartment could generate a $4,800+ deduction using the actual method versus $1,000 simplified. The difference adds up.

One thing that trips people up: if you’re an S-Corp owner, the home office deduction works differently. You’ll need to set up an accountable plan and have the S-Corp reimburse you, rather than claiming it directly on your personal return. Our home office deduction guide walks through the entity-specific rules.

Vehicle and Mileage Deductions

The IRS standard mileage rate for 2025 is $0.70 per mile (increasing to $0.725 for 2026). You can also use the actual expense method, tracking gas, insurance, maintenance, repairs, and depreciation, then applying your business-use percentage.

Standard mileage is simpler and usually works better for fuel-efficient vehicles with lower operating costs. Actual expenses typically produce a bigger deduction for expensive, heavy, or high-maintenance vehicles. You must choose the standard mileage method in the first year you use a vehicle for business if you want to use it in future years.

Section 179 vehicle deduction: SUVs and trucks with a gross vehicle weight rating (GVWR) over 6,000 lbs can be deducted under Section 179. SUVs are capped at $30,500 for the Section 179 portion. Trucks and vans over 6,000 lbs with no passenger seating limitation can qualify for the full deduction. Browse our Section 179 vehicle list to see which models qualify.

Record-keeping matters here. The IRS requires a contemporaneous mileage log showing the date, destination, business purpose, and miles driven for each trip. Apps make this easier — check our mileage tracker recommendations.

Equipment and Depreciation Deductions

This is where OBBBA made the biggest dollar impact for many businesses.

Section 179 expensing lets you deduct the full purchase price of qualifying equipment in the year you buy it, up to $2.5 million (OBBBA limit). Qualifying property includes machinery, equipment, furniture, computers, off-the-shelf software, and certain vehicles. The deduction can’t exceed your business’s taxable income for the year.

Bonus depreciation is back to 100% for qualifying property placed in service after January 19, 2025, thanks to OBBBA. Unlike Section 179, bonus depreciation has no dollar limit and can create a net operating loss. It applies to both new and used property (as long as it’s new to you).

When to use which?

If your business bought a $180,000 piece of equipment in August 2025, you can deduct the entire $180,000 in 2025 using either Section 179 or bonus depreciation. Before OBBBA restored 100% bonus, you’d have been limited to 40% ($72,000) under the phase-down schedule.

Health Insurance and Benefits Deductions

Self-employed health insurance is one of the most valuable deductions available. Sole proprietors, partners, and S-Corp shareholders owning 2% or more can deduct 100% of health insurance premiums for themselves, their spouse, and their dependents. This is an above-the-line deduction, meaning it reduces your adjusted gross income — not just your Schedule C income.

The deduction can’t exceed your net self-employment income. And if you’re eligible for employer-sponsored coverage through a spouse’s job, you can’t claim this deduction for those months.

S-Corp owners: your health insurance premiums must be included in your W-2 wages, then deducted on your personal Form 1040. The mechanics are different from Schedule C filers. See our S-Corp health insurance rules for the step-by-step.

HSA contributions provide a double benefit: tax-deductible going in, tax-free coming out for medical expenses. For 2025, limits are $4,300 (individual) and $8,550 (family), plus $1,000 catch-up if you’re 55 or older. You need a high-deductible health plan (HDHP) to contribute.

Employee benefits you provide — group health plans, life insurance (up to $50,000 group term), disability coverage, dependent care assistance — are fully deductible business expenses.

Retirement Plan Deductions

Retirement contributions are often the single largest deduction a small business owner can take. The numbers for 2025:

Solo 401(k): $23,500 in employee deferrals, plus up to 25% of net self-employment earnings as an employer contribution. Total combined limit: $70,000. If you’re 50-59 or 64+, add $7,500 catch-up ($77,500 total). Ages 60-63 get a $11,250 catch-up under SECURE 2.0 ($81,250 total). Roth option available. This is the best option for most self-employed business owners without employees.

SEP-IRA: Up to 25% of net self-employment earnings, same $70,000 maximum. Simpler to set up than a Solo 401(k). No employee deferral component. Can be established and funded up to your tax filing deadline (including extensions).

SIMPLE IRA: $16,500 employee contribution plus a 3% employer match (2025). Works well for businesses with a small number of employees.

A sole proprietor earning $200,000 in net self-employment income could contribute approximately $55,130 to a Solo 401(k) ($23,500 employee + roughly $31,630 employer). That’s $55,130 off taxable income. At a 32% marginal tax rate, that’s $17,642 in tax savings from this one deduction alone.

For strategies on maximizing retirement deductions by entity type, see our retirement tax planning hub and our guide to Solo 401(k) Roth contributions.

Self-Employment Tax Deductions

Self-employment tax is 15.3% on the first $176,100 of net self-employment income (2025), split between 12.4% Social Security and 2.9% Medicare. Medicare has no cap, and income over $200,000 (single) or $250,000 (joint) gets an additional 0.9% Medicare surtax.

The deduction: you can deduct 50% of your self-employment tax when calculating your adjusted gross income. This isn’t a business deduction — it’s a personal income tax adjustment. But it reduces your AGI, which affects other deductions and credits.

On $150,000 of net Schedule C income, your SE tax is approximately $21,194. The 50% deduction saves you roughly $10,597 in AGI, which could mean $2,500-$3,700 in actual tax savings depending on your bracket.

If your self-employment income is consistently above $60,000-$70,000, the S-Corp election may save significant SE tax through a reasonable salary strategy. Run the numbers with our self-employment tax calculator or compare entity options in our sole proprietor vs LLC vs S-Corp guide. For a deeper look at the tax itself, see our self-employment tax guide.

QBI Deduction (Section 199A)

The qualified business income deduction lets pass-through business owners (sole proprietors, S-Corp shareholders, partners) deduct a percentage of their qualified business income from their personal tax return. For 2025, the rate is 20%. Starting in 2026, OBBBA increases it to 23%.

How it works for 2025: If your taxable income is below $197,300 (single) or $394,600 (married filing jointly), you get the full 20% deduction on your QBI. Above those thresholds, the deduction phases in limitations based on W-2 wages paid and/or the unadjusted basis of qualified property.

Specified service businesses (SSTBs) — including law, accounting, consulting, and healthcare — face additional restrictions. Above the threshold, the deduction phases out entirely over the phase-in range.

What OBBBA changed:

• Rate increases to 23% for tax years beginning after December 31, 2025
• Made permanent (was expiring end of 2025)
• Expanded phase-in range to $75,000 (single) / $150,000 (joint)
• New $400 minimum deduction for QBI of at least $1,000
• Qualified tips excluded from QBI beginning 2025

Quick example (2025): A sole proprietor with $120,000 in qualified business income and taxable income below the threshold gets a QBI deduction of $24,000 (20% x $120,000). In 2026, that same QBI would generate a $27,600 deduction (23% x $120,000) — an extra $3,600 in deductions.

For optimization strategies, see our QBI planning strategies guide or estimate your deduction with our QBI calculator.

Travel, Meals, and Entertainment

Business travel — airfare, hotels, rental cars, rideshares, parking, and tolls — is 100% deductible when the trip is primarily for business. “Primarily” means more than 50% of the trip days involve business activities.

Business meals are 50% deductible. The temporary 100% deduction for restaurant meals expired December 31, 2022. You can deduct 50% of meals with clients, prospects, or employees when business is discussed. Per diem rates are an alternative to tracking actual receipts — the IRS publishes rates by city.

Entertainment is not deductible. Client golf, concert tickets, sporting events — none of it. This hasn’t changed since the Tax Cuts and Jobs Act of 2017.

Documentation required for every deductible meal: the amount, date, place, business purpose, business relationship of the person you’re dining with, and topics discussed. Your credit card statement alone isn’t enough.

Commonly Overlooked Deductions

These are the ones that consistently get missed:

• Startup costs — Up to $5,000 deductible in your first year of business (if total startup costs are under $50,000). The rest amortizes over 15 years. This includes market research, travel to scope out locations, and pre-opening advertising.
• Business loan interest — Interest on business loans, lines of credit, and business credit card balances. The loan proceeds must be used for business purposes.
• State and local business taxes — The business portion of property taxes, state franchise taxes (like Texas’s margin tax), and state income taxes in states that impose them.
• Professional development — Books, industry publications, professional association dues, subscriptions to trade journals.
• Business gifts — Up to $25 per recipient per year. Small, but it adds up if you send gifts to 50+ clients.
• Bad debts — Accounts receivable you can’t collect, if you use accrual accounting. Cash-basis taxpayers can’t deduct bad debts they never reported as income.
• Retirement plan administration — Fees to set up and maintain your Solo 401(k), SEP-IRA, or other retirement plan are deductible business expenses separate from the contributions themselves.

Deductions by Entity Type

Not every deduction works the same way across entity types. Here’s how the major deductions break down:

The entity you operate under affects not just which deductions you can take, but how you take them. A home office deduction on Schedule C is straightforward. The same deduction through an S-Corp requires an accountable plan, corporate reimbursement, and proper documentation.

For entity-specific guidance:

• Schedule C guide for sole proprietors
• S-Corporation tax guide for S-Corp owners
• Partnership taxation guide for partners
• Business entity tax guide for comparing all structures

How to Maximize Your Deductions

1. Track expenses year-round. Reconstructing a year of expenses in March is how deductions get missed. Use accounting software, connect your bank feeds, and categorize transactions monthly. See our bookkeeping basics guide.
2. Separate business and personal finances. A dedicated business bank account and credit card make expense tracking cleaner and audit defense stronger.
3. Time equipment purchases strategically. With 100% bonus depreciation restored, the timing matters less for depreciation purposes, but Section 179’s income limitation means you may want to time purchases in profitable years.
4. Fund retirement accounts before the filing deadline. SEP-IRA contributions can be made up to your tax filing deadline, including extensions. That means an October 15 extension gives you until October 15 to make a contribution that reduces your prior-year taxes.
5. Analyze your entity structure. If you’re a sole proprietor earning over $60,000-$70,000 consistently, an S-Corp election could reduce your self-employment tax by thousands annually. But it comes with payroll requirements and administrative costs. Get entity-specific advice before making the switch — see our guide on how to choose a tax preparer who specializes in your situation.

Frequently Asked Questions

What is the most common tax deduction for small businesses?

The home office deduction and vehicle mileage deduction are the most frequently claimed. But the QBI deduction and retirement contributions typically produce the largest dollar savings for business owners earning over $100,000. A sole proprietor with $150,000 in QBI saves $30,000 in deductions from QBI alone (20% for 2025).

What changed for small business deductions under OBBBA?

The One Big Beautiful Bill Act (signed July 2025) made the QBI deduction permanent and increased it to 23% starting 2026. It raised Section 179 to $2.5 million, permanently restored 100% bonus depreciation for property placed in service after January 19, 2025, and made domestic R&D expenses immediately deductible again.

Can I deduct health insurance premiums as a small business owner?

Self-employed individuals — sole proprietors, partners, and S-Corp shareholders owning 2% or more — can deduct 100% of health, dental, and vision insurance premiums for themselves, their spouse, and dependents. This is an above-the-line deduction that reduces your adjusted gross income. The deduction can’t exceed your net self-employment income.

How much can I deduct for a home office in 2025?

Using the simplified method, $5 per square foot up to 300 square feet ($1,500 maximum). Using the actual expense method, you deduct a percentage of your home expenses based on the square footage of your dedicated office space. The actual method often produces a larger deduction but requires tracking mortgage/rent, utilities, insurance, and other household expenses.

Should I take the standard mileage rate or actual expenses?

The standard rate ($0.70/mile for 2025) is simpler and works well for fuel-efficient vehicles. Actual expenses — gas, insurance, repairs, depreciation — typically produce a bigger deduction for expensive or heavy vehicles. You must elect the standard mileage method in the first year you use a vehicle for business if you want to use it going forward.

What’s the difference between Section 179 and bonus depreciation?

Both let you deduct equipment costs in the year of purchase. Section 179 has a $2.5 million annual cap and can’t create a business loss. Bonus depreciation has no dollar cap and can create a loss. Under OBBBA, bonus depreciation is back to 100% permanently for qualifying property placed in service after January 19, 2025. Both apply to new and used property.

Do I need receipts for all business deductions?

The IRS requires documentation for all deductions. For expenses under $75, a bank or credit card statement showing the amount, date, and vendor may be sufficient. For larger expenses, keep itemized receipts. Mileage requires a contemporaneous log with date, destination, business purpose, and miles. Missing documentation is the number one reason deductions get denied in an audit.

Is the QBI deduction 20% or 23%?

For 2025 tax returns, the QBI deduction is 20%. OBBBA increased it to 23% for tax years beginning after December 31, 2025 — so your 2026 return will use the higher rate. OBBBA also made the deduction permanent; it was previously set to expire at the end of 2025.

What to Do Next

OBBBA made 2025 and 2026 the most deduction-friendly years for small business owners in recent memory. Between restored bonus depreciation, higher Section 179 limits, and the QBI increase coming in 2026, there’s more to work with than most business owners realize.

But the deductions that save the most money — retirement contributions, entity structure optimization, strategic equipment timing — require planning before year-end. Not after.

If you haven’t analyzed how OBBBA affects your specific business entity, now is the time. We specialize in tax planning strategies for small business owners across every entity type — Schedule C, S-Corp, and partnerships. Schedule a free tax planning assessment and we’ll identify which deductions apply to your situation and how to maximize them.

For more on sole proprietor deductions specifically, see our Schedule C deductions guide.