Small Business Tax Preparation Checklist: What to Gather Before Filing

Updated September 7, 2026 for tax-year 2025 returns filed in 2026, with the 2026 figures noted where they change. Download the printable checklist (PDF).

The short answer: a business tax return is prepared from three things — reconciled books, the documents that support them, and the facts about the business that changed during the year. Gather those in the order below and the return gets done at the base price, without the back-and-forth that turns a two-week engagement into a two-month one. The checklist starts with what every business needs, then adds the items that are specific to sole proprietors (Schedule C), partnerships (Form 1065), S corporations (Form 1120-S) and C corporations (Form 1120).

Key 2026 filing dates

An extension extends the time to file, not the time to pay. For tax-year 2026 returns, the partnership and S corp deadline moves to March 15, 2027.

Part 1: for every business

Reconciled books

• Profit and loss and balance sheet for the full year, with every bank, credit card, loan and payment-processor account reconciled to its statements through December 31.
• Access to the QuickBooks, Xero or spreadsheet file, or an export of the general ledger.
• If the books are not reconciled, this is the first job: catch-up bookkeeping is scoped before the return, and clients on a monthly bookkeeping plan skip this step entirely.

Statements and year-end balances

• December 31 statements for every business bank and credit card account.
• Loan statements showing the year-end balance and interest paid (Form 1098 for real estate loans).
• Merchant and platform reports: Stripe, Square, PayPal, Shopify, Amazon. A Form 1099-K arrives only if you exceeded $20,000 and 200 transactions on a platform in 2025; the income is reportable either way.

Income records

• Forms 1099-NEC and 1099-MISC received.
• Invoices issued and the accounts receivable balance at year end (for accrual-basis businesses).
• Any income not through the bank: cash sales, barter, personal accounts used for business.

Expense support

• Receipts or invoices for larger purchases, travel and meals (statements alone do not document the business purpose).
• Vehicle: total miles and business miles for the year, or actual costs if you use that method. The 2025 standard rate is 70 cents per business mile; the 2026 rate is 72.5 cents.
• Home office: square footage of the office and of the home. The simplified method allows $5 per square foot up to 300 square feet.
• Health insurance premiums paid for the owner and family.
• Retirement contributions made or planned for the year (SEP, SIMPLE, solo 401(k)).

Payroll and contractors

• Forms W-2 and W-3, and Forms 941 (quarterly) and 940 (annual), or your payroll provider’s year-end package.
• Forms 1099-NEC issued to contractors paid $600 or more in 2025. For payments made in 2026 the threshold rises to $2,000.
• Form W-9 on file for every contractor.

Assets

• A list of equipment, vehicles, furniture and software bought during the year with date and cost, and anything sold, traded or scrapped.
• Last year’s depreciation schedule.
• For tax-year 2025, up to $2,500,000 of qualifying property can be expensed under Section 179, and 100% bonus depreciation applies to qualified property acquired and placed in service after January 19, 2025. Whether to use them is a planning decision, not a default, so we ask before applying either.

Taxes already paid

• Federal and state estimated tax payments made, with dates and amounts.
• Prior-year overpayment applied to this year.
• State annual taxes and fees paid (for California LLCs, the $800 annual tax and any LLC fee).

Prior returns and notices

• Last year’s complete business return (and personal return for a Schedule C or K-1 recipient) — it carries forward depreciation, losses and basis.
• Any IRS or state letter received during the year, opened or not.

Part 2: by entity type

Sole proprietor or single-member LLC (Schedule C)

• Everything in Part 1, plus the owner’s personal documents, because Schedule C files inside the Form 1040.
• Self-employed health insurance premiums (deducted on Form 7206).
• Qualified business income: the 20% deduction phases down for 2025 taxable income above $197,300 (single) or $394,600 (joint) for specified service businesses, so the personal-side income matters.
• Estimated payments made through the owner’s Social Security number.

Partnership or multi-member LLC (Form 1065)

• The partnership or operating agreement, with any amendments during the year.
• Each partner’s name, address, tax ID, ownership percentage and any change during the year.
• Contributions and distributions by partner, including property.
• Guaranteed payments to partners.
• Prior-year K-1s and capital account balances (reported on a tax basis).
• Details on our partnership tax return preparation page.

S corporation (Form 1120-S)

• Officer compensation: W-2 wages paid to each shareholder-employee, which the IRS expects to be reasonable before distributions are taken.
• Distributions to each shareholder by date.
• Shareholder health insurance premiums paid by the corporation (included in the shareholder’s W-2).
• Shareholder loans to or from the corporation.
• Prior-year K-1s and basis records; shareholders who claim a loss, receive a distribution or repay a loan file Form 7203 with their personal return.
• Any accumulated earnings and profits from C corporation years.
• Details on our S corp tax preparation page.

C corporation (Form 1120)

• Corporate minutes or resolutions for dividends, officer compensation and major transactions.
• Dividends paid to shareholders (Forms 1099-DIV issued).
• Estimated tax payments made by the corporation.
• Net operating loss carryforwards and credit carryforwards from prior years.
• State franchise tax payments and filings.

Part 3: facts that change the return

Tell your preparer if any of these happened during the year, because each changes how the return is prepared:

• A new owner, a departing owner, or a change in ownership percentages.
• An entity election filed or accepted (Form 2553 for S corporation status, Form 8832).
• Operations, employees, property or sales in a new state.
• A business bought, sold, started or closed.
• A loan taken, forgiven or refinanced.
• A large asset purchase or sale, including vehicles.
• Inventory on hand at year end, if you sell products.
• Crypto or other digital assets received or spent by the business.

What you do not need

Every receipt. Statements are the backbone; receipts matter for larger, unusual or mixed-use items. And beneficial ownership reporting to FinCEN: after the March 2025 interim rule and the final rule effective August 14, 2026, companies created in the United States are exempt, so no BOI report is needed for a domestic LLC or corporation.

Where to send it

Clients upload everything to a secure portal; nothing goes by email attachment. If you are missing items, send what you have and list the rest — most gaps (a lost 1099, a missing statement month) are recoverable from the issuer or from IRS transcripts. Our business tax preparation page covers pricing by return type, and Get Started takes you to the right intake for your entity.

Sources

• IRS, Publication 509, Tax Calendars (2026) — irs.gov
• IRS, 2026 standard mileage rates (IR-2025-128) — irs.gov
• IRS, Instructions for Forms 1099-MISC and 1099-NEC — irs.gov
• IRS, Form 1099-K threshold FAQs — irs.gov
• IRS, Instructions for Form 4562 (Section 179 and bonus depreciation) — irs.gov
• IRS, Simplified option for home office deduction — irs.gov
• IRS, Instructions for Form 8995 (QBI thresholds) — irs.gov
• IRS, Instructions for Form 7203 — irs.gov
• FinCEN, Beneficial ownership information — fincen.gov