Small Business Tax Deduction Checklist: 40+ Commonly Missed Deductions
Most small business owners miss deductions because they do not know they are available or they lack the documentation to support them. This checklist covers the most commonly missed deductions, organized by category. Every item on this list is a legitimate business deduction when the expense is ordinary and necessary for the business under IRC 162.
Commonly missed deductions by category:
Office and workspace:
- Home office (simplified: $5/sq ft up to $1,500; actual: pro-rated home expenses)
- Coworking space membership
- Office furniture (Section 179 or de minimis if under $2,500)
- Office supplies (paper, ink, postage, shipping materials)
Technology and software:
- Computer and equipment purchases (Section 179)
- Software subscriptions (QuickBooks, Adobe, project management tools)
- Website hosting, domain registration, and design
- Cloud storage and backup services
- Cell phone (business-use percentage)
- Internet service (business-use percentage for home office)
Vehicle and travel:
- Business mileage (70 cents/mile for 2025, or actual expenses)
- Parking fees and tolls (deductible in addition to mileage rate)
- Business travel (airfare, hotel, ground transportation)
- Meals during business travel (50% deductible)
- Baggage fees during business travel
Professional development:
- Courses, seminars, and conferences (related to current business)
- Books, publications, and trade journals
- Professional certifications and licenses
- Industry association memberships and dues
Marketing and client acquisition:
- Google Ads, Facebook Ads, LinkedIn Ads
- Business cards, brochures, and printed materials
- Trade show booth rental and materials
- Client gifts (up to $25 per recipient per year)
- Website SEO and content marketing services
Insurance:
- General liability insurance
- Professional liability/E&O insurance
- Commercial auto insurance (business vehicle)
- Workers’ compensation insurance
- Cyber liability insurance
- Business interruption insurance
Financial:
- Bank fees on business accounts
- Credit card processing fees (Stripe, Square, PayPal)
- Business credit card annual fees
- Interest on business loans and credit cards
- Accounting and bookkeeping fees
- Tax preparation fees (Schedule C portion)
Legal and compliance:
- Legal fees (contract drafting, business formation, trademark)
- State business registration fees
- Business licenses and permits
- Regulatory compliance costs
Employees and contractors:
- Wages, salaries, and bonuses
- Employer payroll taxes (FICA, FUTA, SUTA)
- Employee benefits (health insurance, retirement plan contributions)
- Independent contractor payments
- Recruitment and hiring costs
Often overlooked:
- Bad debts written off (accrual method; cash basis can deduct cost of goods for inventory)
- Self-employed health insurance premiums (Form 1040 line 17, not Schedule C)
- Retirement plan contributions (Solo 401(k), SEP IRA)
- HSA contributions (Form 1040 line 13)
- 50% of self-employment tax (Form 1040 Schedule 1)
- State and local business taxes (not subject to the $40,000 SALT cap)
- Business use of personal assets (allocated percentage)
How much are missed deductions costing you?
The average small business owner who prepares their own return misses $5,000-$10,000 in legitimate deductions per year. At a 32% tax bracket (plus 15.3% SE tax), each $1,000 in missed deductions costs approximately $460 in unnecessary taxes. Over 5 years, $5,000 in annual missed deductions costs $11,500 in extra taxes.
The most commonly missed categories are: home office (many business owners believe it triggers audits, which is a myth), vehicle expenses (no mileage log = no deduction), retirement plan contributions (not set up), and professional development (not tracked).
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Yarik Yarosh, CPA. "Small Business Tax Deduction Checklist: 40+ Commonly Missed Deductions." Blue Cloud CPA, September 5, 2026. https://bluecloudcpa.com/guides/small-business-tax-deduction-checklist
This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.