How do you file business taxes?

Filing deadlines by entity type

• Sole proprietorship (Schedule C, attached to Form 1040) — April 15.
• Partnership (Form 1065) — March 15 for calendar-year partnerships.
• S-Corporation (Form 1120-S) — March 15 for calendar-year S-corps.
• C-Corporation (Form 1120) — April 15 for calendar-year C-corps.
• Fiscal-year businesses — generally 75 days after fiscal year-end (partnerships/S-corps) or 105 days after year-end (C-corps).
• Extensions: 6-month extension available (Form 7004 for business returns, Form 4868 for individual). Extension to file ≠ extension to pay — estimated taxes still due on original deadline.

Required forms by entity

The IRS Small Business & Self-Employed Tax Center at irs.gov/businesses/small-businesses-self-employed has the full form library for each entity type. Key forms:

• Schedule C (Form 1040) — sole proprietors report business income and expenses on this schedule, attached to personal return.
• Form 1065 — partnership information return; each partner receives Schedule K-1 showing their share of income.
• Form 1120-S — S-corporation information return; shareholders receive Schedule K-1.
• Form 1120 — C-corporation tax return; the corporation itself pays corporate income tax.
• Form 941 — quarterly payroll tax return if you have employees (filed separately from income taxes).
• Form 1099-NEC — report payments to independent contractors of $600+ (due January 31).

Documents to gather before filing

• 12 months of business bank statements — reconcile to gross receipts on the return.
• Profit & loss statement (P&L) — income, COGS, and operating expenses organized by category.
• Balance sheet — assets, liabilities, and equity as of year-end.
• Mileage log — required to deduct vehicle use; the IRS standard mileage rate changes annually.
• Asset purchase records — equipment, vehicles, furniture bought during the year for Section 179 or MACRS depreciation.
• Payroll records — W-2s issued, quarterly 941s filed, payroll tax deposits.
• Receipts for deductible expenses — meals (50% deductible), travel, professional services, advertising.

Key deductions for small businesses

• Section 179 — immediate first-year expensing of qualifying equipment and business property. The 2026 Section 179 deduction limit is $2,560,000 per IRS Publication 946, up from $1,220,000 in 2024, per the One Big Beautiful Bill Act.
• Home office deduction — requires exclusive-and-regular business use of a defined home space; either simplified method ($5/sq ft up to 300 sq ft) or actual expense method.
• Vehicle deduction — business mileage at the IRS standard rate, or actual vehicle expenses allocated to business use percentage.
• Professional services — attorney, accountant, and consultant fees paid for business purposes are fully deductible.
• Business interest expense — interest paid on business loans is deductible (subject to Section 163(j) limitations for larger businesses).
• Qualified Business Income (QBI) deduction — pass-through entities may deduct up to 20% of qualified business income under Section 199A.

When to use a CPA

Use a CPA if: you have employees, own business real estate, have multiple owners, made significant equipment purchases, received a large contract, had revenue above $500K, or received an IRS notice. Tax complexity rises sharply with employee count and entity type — the cost of a CPA is itself a deductible professional expense.

Apply at ClearValue Lending

Lenders require 2 years of business tax returns for most SBA and term loans. ClearValue Lending connects small businesses to lenders who work with sole proprietors, LLCs, S-corps, and C-corps across the full range of financing products. Apply through the ClearValue Lending portal when your tax returns are filed and current.