How to File Your Business Taxes Without a CPA

File business taxes yourself using the right forms, software, and documentation strategies for your entity type.

1. Choose software based on entity type. LLC filing Schedule C needs basic software ($50-150). S-Corp filing Form 1120S requires business-grade software ($200-500). Partnerships filing Form 1065 need multi-user capability ($300-800). Free options work only for the simplest sole proprietorships.
2. Gather your numbers in order. Pull gross revenue, cost of goods sold, and operating expenses from your P&L. Collect 1099s, W-2s, and depreciation schedules. Reconcile credit card statements and bank deposits. Missing documentation kills DIY filing faster than complexity.
3. Know your deduction categories. Business meals at 50%, vehicle expenses via mileage or actual costs, home office at $5 per square foot up to 300 sq ft. Equipment over $2,500 gets depreciated unless you elect Section 179. Keep receipts digital and categorized.
4. File estimated taxes quarterly. Pay 25% of expected annual tax liability by Jan 15, Apr 15, Jun 15, Sep 15. Underpayment penalty kicks in at $1,000 owed. Use Form 1040ES for quarterly payments. Safe harbor: pay 110% of last year's tax if AGI exceeded $150,000.
5. Double-check before submitting. Verify EIN matches bank accounts. Confirm revenue ties to 1099s received. Run the software's error check twice. Print and store copies for 7 years minimum. E-file by March 15 for partnerships/S-Corps, April 15 for LLCs.