A thorough tax deductions checklist is the difference between overpaying the IRS and keeping thousands of dollars in your business. The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, made sweeping changes effective for 2026 tax returns — including a higher Qualified Business Income deduction, restored 100% bonus depreciation, and an increased Section 179 limit. This checklist covers every deduction available to small business owners, organized by category with current dollar limits so you can hand it directly to your CPA.

In our 20+ years providing bookkeeping services to thousands of businesses, we have seen the same pattern: business owners who track deductions throughout the year claim $5,000 to $20,000 more than those who scramble at tax time. The checklist below ensures nothing falls through the cracks — but it only works if your books are accurate and current.

What Changed for 2026: OBBBA Tax Updates

Before walking through the checklist, here are the major changes that affect your 2026 deductions. These come from the One Big Beautiful Bill Act and updated IRS guidance:

These changes mean larger deductions across the board for 2026. The rest of this checklist reflects these updated limits.

Business Operating Expense Deductions

These are the day-to-day costs of running your business. Every one of them is deductible if it is ordinary (common in your industry) and necessary (helpful for your business):

• Rent and lease payments — office space, warehouse, retail location, or equipment leases. Fully deductible in the year paid.
• Utilities — electricity, water, gas, internet, and phone service for your business location.
• Office supplies and equipment — computers, printers, desks, paper, ink, and any supplies used in daily operations. Items under $2,500 can be expensed immediately under the de minimis safe harbor rule.
• Software subscriptions — accounting software, project management tools, CRM systems, cloud storage, and any SaaS products used for business.
• Business insurance — general liability, professional liability (E&O), property insurance, cyber liability, and workers’ compensation premiums.
• Advertising and marketing — website hosting, Google Ads, social media advertising, print materials, business cards, and SEO services.
• Professional services — fees paid to attorneys, CPAs, professional bookkeeping support, consultants, and other professionals.
• Bank and payment processing fees — monthly bank fees, credit card processing fees, PayPal and Stripe transaction fees, and merchant account charges.
• Postage and shipping — stamps, courier services, FedEx/UPS charges, and packaging materials.

Employee and Contractor Deductions

Labor costs are typically the largest deductible expense for businesses with staff:

• Wages and salaries — all compensation paid to employees, including bonuses and commissions.
• Payroll taxes — the employer portion of Social Security (6.2%) and Medicare (1.45%) taxes, plus federal and state unemployment taxes. Your payroll service should track these automatically.
• Employee benefits — health insurance premiums, retirement plan contributions, life insurance, disability insurance, and employee assistance programs.
• Contractor payments — fees paid to independent contractors and freelancers. For 2026, you must issue Form 1099-NEC for payments totaling $2,000 or more per contractor (up from $600). See our 1099 filing guide for deadlines.
• Education and training — courses, certifications, seminars, conferences, and professional development for yourself and your employees, provided they maintain or improve skills required for the business.
• Employee gifts — deductible up to $25 per person per year.

Home Office Deduction

If you use a dedicated space in your home exclusively and regularly for business, you qualify for the home office deduction. You have two methods:

The regular method often yields a larger deduction but requires tracking actual expenses throughout the year. This is where consistent a structured bookkeeping checklist pays for itself — without categorized records, most business owners default to the simplified method and leave money on the table.

Vehicle and Travel Deductions

Business travel is fully deductible, but documentation requirements are strict. The IRS requires a contemporaneous log — meaning you must record trips as they happen, not reconstruct them at year-end:

• Standard mileage rate — 72.5 cents per business mile for 2026. A business owner driving 15,000 business miles claims $10,875 in deductions. You must log the date, destination, business purpose, and odometer readings for every trip.
• Actual vehicle expenses — alternatively, deduct the business-use percentage of gas, insurance, repairs, depreciation, lease payments, registration, and parking. You cannot switch between methods year to year for the same vehicle if you used actual expenses in the first year.
• Air travel — flights for business purposes are fully deductible. If you combine business and personal travel, only the business portion is deductible.
• Lodging — hotel costs during business travel, including reasonable incidentals like laundry and tips.
• Meals during travel — 50% of meal costs while traveling for business. The temporary 100% deduction for restaurant meals expired after 2022.
• Parking and tolls — business-related parking fees and tolls are 100% deductible regardless of whether you use the standard mileage rate or actual expenses.

Depreciation and Equipment Deductions

Large purchases do not have to be spread across multiple years. The 2026 rules give business owners three powerful options:

The key difference: Section 179 is limited to your taxable income (you cannot create a loss), while bonus depreciation can generate a net operating loss that carries forward. Your CPA needs accurate asset records and financial reports to determine which method saves you the most.

Retirement Plan Deductions

Retirement contributions are one of the most powerful deductions because they reduce your current tax bill while building long-term wealth. The 2026 limits are:

• Solo 401(k) — $23,500 employee contribution ($31,000 if age 50+) plus up to 25% of compensation as an employer contribution, for a combined maximum of $70,000. Best for self-employed with no employees.
• SEP-IRA — up to 25% of net self-employment income, maximum $70,000. Simple to set up, no employee contribution component.
• SIMPLE IRA — $16,500 employee contribution ($20,000 if age 50+) with mandatory employer match up to 3%. Best for businesses with fewer than 100 employees.
• Traditional IRA — $7,000 ($8,000 if age 50+). Deductibility depends on income and whether you have an employer plan. See the 2026 tax brackets to determine your eligibility.
• Health Savings Account (HSA) — $4,300 individual / $8,550 family. Triple tax benefit: contributions are deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. Requires enrollment in a high-deductible health plan.

Qualified Business Income (QBI) Deduction

The QBI deduction is the single largest deduction available to most pass-through business owners — and OBBBA just made it bigger. For 2026 returns, you can deduct 23% of your qualified business income (up from 20%). This deduction applies to sole proprietors, S-corporation shareholders, partners, and most LLC members.

To qualify for the full deduction, your total taxable income must be below the threshold: $197,300 for single filers and $394,600 for joint filers (2026 amounts). Above those thresholds, the deduction phases out for specified service trades (law, medicine, consulting, athletics, financial services) and becomes limited by W-2 wages paid or property held for other business types. Accurate income tracking through professional bank reconciliation ensures you know exactly where you stand relative to these thresholds.

Insurance and Health Deductions

• Self-employed health insurance — if you are self-employed and not eligible for employer-sponsored coverage through a spouse, you can deduct 100% of health, dental, and long-term care insurance premiums for yourself, your spouse, and dependents. This is an above-the-line deduction (reduces AGI).
• Business insurance premiums — general liability, professional liability, property, product liability, cyber insurance, and business interruption insurance.
• Workers’ compensation — required in most states, fully deductible.
• Key person insurance — premiums on life insurance policies where the business is the beneficiary are NOT deductible. However, the proceeds are generally tax-free.

Interest and Debt Deductions

• Business loan interest — interest on loans used for business purposes, including SBA loans, lines of credit, and equipment financing.
• Credit card interest — interest on business credit card balances (personal credit card interest is never deductible, even if used for business purchases).
• Mortgage interest on business property — interest on a mortgage for property used in your business.
• Vehicle loan interest — the business-use percentage of interest on a car loan, if using the actual expense method instead of standard mileage.

Tax and License Deductions

• State and local business taxes — state income tax, franchise taxes, and local business privilege taxes.
• Property taxes on business property — real estate taxes on business-owned buildings and land.
• Self-employment tax — you can deduct the employer-equivalent portion (50%) of self-employment tax as an above-the-line deduction.
• Business licenses and permits — annual license fees, professional certifications, and regulatory permits.
• Sales tax paid on business purchases — deductible as part of the cost of the item purchased.

Documentation Rules: What the IRS Requires

Claiming deductions without proper documentation is the fastest way to lose them in an audit. Here are the IRS requirements:

A dedicated bookkeeping team captures and categorizes every transaction as it happens — which is far more reliable than reconstructing records at tax time. If your books are behind, our catch-up bookkeeping service can bring them current before your filing deadline.

Deductions Commonly Missed by Small Business Owners

These deductions are legitimate but frequently overlooked because business owners either do not know about them or lack the records to claim them:

• Business use of personal cell phone — the business-use percentage of your monthly phone bill is deductible. Track your business calls or estimate the percentage and document your methodology.
• Start-up costs — up to $5,000 in business start-up costs can be deducted in the first year. The remainder is amortized over 15 years. This includes market research, advertising before opening, employee training, and travel to set up the business.
• Bad debts — if a customer owes you money and you have exhausted reasonable collection efforts, you can write off the unpaid amount as a bad debt deduction.
• Charitable contributions through the business — C-corporations can deduct charitable contributions up to 10% of taxable income. Pass-through entities report charitable contributions on the owner’s personal return.
• Energy-efficient improvements — the Energy Efficient Commercial Buildings Deduction (Section 179D) allows up to $5.65 per square foot for qualifying improvements to lighting, HVAC, and building envelope.
• Research and development (R&D) credit — small businesses with less than $5 million in gross receipts can offset up to $500,000 in payroll taxes with the R&D credit. This applies to developing new products, processes, or software.
• State-specific deductions — many states offer additional deductions and credits not available at the federal level. Your CPA should review state-specific opportunities based on where your business operates.