The year-end checklist that makes tax season boring

Tax season is only stressful when the year behind you is a mystery. If your accounts are reconciled and your documents are in one place by mid-January, filing becomes a hand-off, not a crisis. Here is the exact checklist we run for our own clients.

Key takeaways

Your CPA needs about a dozen documents — collect them as they arrive, not in April.
Reconcile every account through December 31 before anything goes to your tax preparer.
Start in October. Two hours a month beats twenty hours in one panicked weekend.
1099s for contractors are due January 31 — earlier than most owners expect.

The documents your CPA will actually ask for

Keep one folder — physical or digital — and drop these in as they show up. Most arrive in January.

Bank & credit card statementsEvery business account, January through December. Your preparer uses the December statements to verify ending balances.

Loan statementsYear-end balance and total interest paid for every business loan, line of credit, and financed vehicle or equipment.

Payroll reportsAnnual payroll summary, W-3, and copies of W-2s if you have employees. Your payroll provider generates these.

1099s you received1099-NEC and 1099-K forms from clients and payment processors. They should match the income already in your books.

1099s you issuedCopies of the 1099-NEC forms you filed for contractors you paid $600 or more.

Asset purchasesInvoices for equipment, vehicles, computers, or furniture bought this year — anything your CPA may depreciate or expense.

Mileage logTotal business miles for the year, with dates and purposes. A mileage app export counts.

Home office numbersSquare footage of the office and the home, plus annual rent or mortgage interest, utilities, and insurance if you claim actual expenses.

Health insurance premiumsSelf-employed owners can often deduct premiums — but only if someone knows the number.

Estimated payments madeDates and amounts of every federal and state estimated tax payment. Missing one causes mismatched notices later.

Last year's returnIf you're working with a new preparer, the prior-year return answers half their questions before they ask.

What to reconcile before anything gets filed

Documents prove the numbers; reconciliation proves the books. Before your CPA sees anything:

Every bank and credit card account reconciled through December 31 — the balance in your books matches the statement to the penny.
Loan balances in your books match the lender's year-end statement, with payments split correctly between principal and interest.
Payroll in the books matches the W-3. If your P&L says one wage number and your payroll filings say another, that gets sorted now, not during an audit.
Accounts receivable and payable cleaned up. Write off invoices that will never be paid; make sure unpaid bills are actually recorded.
Owner draws and contributions categorized as such — not as expenses or income.

The timeline

October

Reconcile everything through September. Look at your year-to-date profit and, if the number is bigger than expected, this is the moment to talk to your CPA about it — while there are still months left to act. A projection conversation in October is worth ten in April.

November

Collect a W-9 from every contractor you've paid this year, while they still return your calls. Review your fixed assets: anything bought, sold, or scrapped gets documented now.

December

Make any planned year-end purchases or retirement contributions with your CPA's input, not on a rumor. Reconcile through November so only one month remains.

January

Reconcile December the first week the statements arrive. File 1099-NEC forms by January 31 — this deadline arrives before most people have thought about taxes at all. Close the year.

February

Send the complete package to your preparer: full-year P&L, balance sheet, and the document folder. Early packages get unhurried attention.

March & April

Review the draft return, ask your questions, file. If anything is genuinely unresolved, extend without guilt — an extension gives you more time to file, not more time to pay, so pay the estimate with it.

From our desk

The single biggest cause of expensive tax prep bills isn't complexity — it's reconstruction. When a CPA has to rebuild a year of books from bank statements before they can file, you pay accountant rates for bookkeeper work. Clean books all year are cheaper than clean-up in April.

This guide is general information for small business owners — not tax, legal, or accounting advice for your specific situation. Talk to your CPA, or to us, before acting on it.

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The year-end checklist that makes tax season boring.