Quick Summary:

  • Organization Maximizes Write-Offs: Self-employed individuals and business owners often miss thousands in valid deductions due to unorganized expense tracking.
  • Core Business Tax Documents: Income records (1099-NEC, 1099-K), expense ledgers, home office metrics, asset purchases, and quarterly estimated tax payments.
  • Schedule C & Corporate Preparedness: Tailored guidance whether you file as a Sole Proprietor, Single-Member LLC, S-Corporation, or Partnership.
  • Missouri & St. Louis Tax Compliance: Stay fully compliant with state sales tax collections, state unemployment taxes, and the 1% St. Louis City Earnings Tax.
  • Get Professional CPA Help: Contact STL Tax or call our South City office on Gravois Road at (314) 645-1614 to schedule your business tax consultation.

Running a self-employed business, freelance practice, or small company in Greater St. Louis comes with endless responsibilities. Whether you operate a specialty trade business in Kirkwood, manage a consulting agency in West County, or run an online shop from your home in Maplewood, tax season presents both unique challenges and major opportunities to save.

Unlike W-2 employees who have income taxes withheld automatically, self-employed taxpayers are responsible for paying their own income tax as well as the 15.3% Self-Employment Tax (Social Security and Medicare).

The single best defense against overpaying your business taxes is keeping immaculate records. STL Tax has compiled this comprehensive Self-Employed & Small Business Tax Checklist to help you gather every document needed to maximize write-offs and protect your bottom line.

1. General Business Information & Corporate Setup

Before analyzing numbers, your CPA needs to establish your business structure and official tax profiles.

  • [ ] Federal Employer Identification Number (FEIN): Or Social Security Number if operating as a sole proprietor.
  • [ ] State Tax IDs: Missouri Department of Revenue Tax ID for sales tax and state payroll withholding.
  • [ ] Entity Documentation: Articles of Organization (LLC), Corporate Charter, or IRS S-Corporation Election Letter (Form 2553).
  • [ ] Prior Year Tax Returns: Federal Form 1040 (Schedule C), Form 1120-S, or Form 1065 from the past 1–3 years.
  • [ ] Ownership Structure Details: Names, SSNs, addresses, and ownership percentages for all partners or shareholders.

2. Gross Business Income & Sales Records

The IRS receives copies of all payment forms reported under your SSN or FEIN. Be prepared to account for all revenue streams:

  • [ ] Form 1099-NEC / 1099-MISC: Statements received from clients for non-employee compensation.
  • [ ] Form 1099-K: Payment processor summaries from Stripe, Square, PayPal, Venmo, Etsy, or merchant accounts.
  • [ ] Gross Sales Ledger / Bank Deposits: Total cash, check, or direct invoicing income not reported on 1099 forms.
  • [ ] Returns and Allowances: Documentation of customer refunds, discounts, or credit memos.

3. Business Expenses & Tax Deductions Checklist

Deductions directly reduce your net taxable income. Organize your receipts or cloud accounting software into clear categories:

Operating & Administrative Costs

  • [ ] Advertising & Marketing: Website hosting, SEO services, social media ads, business cards, and print materials.
  • [ ] Software & Subscriptions: QuickBooks, CRM tools, cloud storage, domain names, and industry software.
  • [ ] Professional Fees: Legal fees, accounting services, and business consulting fees.
  • [ ] Office Supplies: Paper, ink, desk accessories, and shipping materials.
  • [ ] Insurance: Commercial liability, professional indemnity, and business property insurance premiums.
  • [ ] Rent & Utilities: Commercial lease payments, building utilities, and business phone lines.

Vehicle & Mileage Expenses

  • [ ] Annual Vehicle Mileage Log: Total business miles driven during the tax year, total personal miles, and commuting miles.
  • [ ] Actual Vehicle Expenses (If Not Using Standard Rate): Fuel receipts, oil changes, repairs, tires, auto insurance, and vehicle loan interest.

Home Office Deduction

  • [ ] Square Footage: Dedicated square footage of home office workspace vs. total square footage of the home.
  • [ ] Home Expenses: Annual homeowner’s insurance, mortgage interest, real estate taxes, HOA fees, electric, gas, and internet bills.

Equipment & Capital Purchases

  • [ ] Major Equipment Purchases: Receipts, purchase dates, and descriptions for computers, machinery, tools, or furniture eligible for Section 179 depreciation.

Meals & Travel

  • [ ] Business Travel: Lodging, airfare, rideshare, and car rental costs for out-of-town business trips.
  • [ ] Business Meals: Receipts and notes detailing the business purpose and attendees for client or prospect meals.

4. Owner Benefits, Payroll & Contractor Payments

Properly documenting payments to yourself and others is critical for tax compliance:

  • [ ] Self-Employed Health Insurance: Total medical, dental, and long-term care insurance premiums paid for yourself and your family.
  • [ ] Form 1099-NEC Issued: Copies of 1099-NEC forms issued to independent contractors paid $600 or more.
  • [ ] Payroll Summaries (Form 941 / 940): Annual payroll reports, W-2 copies, and tax deposit receipts if you have W-2 employees.
  • [ ] S-Corp Officer Compensation: W-2 statements showing reasonable salary paid to S-Corp owner-employees.
  • [ ] Retirement Contributions: Contributions made to a SEP-IRA, Solo 401(k), or SIMPLE IRA.

5. Missouri & Local St. Louis Tax Documents

Ensure your business complies with local tax jurisdiction requirements:

  • [ ] Missouri Sales Tax Filings: Annual or quarterly returns submitted to the Missouri Department of Revenue.
  • [ ] St. Louis City Earnings Tax Forms: Form E-1 or Form E-23 filings detailing the 1% city tax on business profits or employee wages (administered by the St. Louis Collector of Revenue).
  • [ ] Quarterly Estimated Tax Receipts: Payment dates and amounts for Federal (Form 1040-ES) and Missouri (Form MO-1040ES) estimated tax payments.

Real-World Case Study: Self-Employed Tax Savings

Meet Jason: Jason is an independent IT consultant living in South County St. Louis. Operating as a single-member LLC, Jason tracked his income carefully but relied on generic credit card statements at tax time, missing out on nuanced write-offs.

Jason brought his financial records to STL Tax.

  • The Action: CPA James Coats used this tax prep checklist to review Jason’s accounts. They uncovered unrecorded home office square footage, missed cell phone and internet allocations, and unlogged business mileage.
  • The Result: STL Tax reduced Jason’s net self-employment income, saving him $3,650 in federal self-employment and Missouri state income taxes.

Partner with St. Louis Business Tax Experts

Don’t leave your hard-earned business revenue on the table. Partner with experienced local CPAs who understand self-employed tax strategies and Missouri business compliance.

At STL Tax, we specialize in small business tax preparation, QuickBooks setup, payroll services, and IRS tax problem resolution throughout Greater St. Louis.

Call our St. Louis office today at (314) 645-1614 or schedule your small business tax consultation online.

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James Coats Certified Public Accountant
Founder & Lead CPA, STL Tax James Coats is a Certified Public Accountant (CPA) and the founder of STL Tax. With over 15 years of professional experience across small businesses, Fortune 500 corporations, government agencies, and non-profit organizations, James brings comprehensive expertise to complex tax and accounting challenges. Based in the South County area of St. Louis, James takes a practical, hands-on approach to demystifying tax laws for individuals and business owners throughout the Greater St. Louis area.
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