How to Prepare Your Small Business Books for Tax Season
To get ready for 2026 returns, close and reconcile December by mid-January, send W-2s and 1099-NECs by February 1, 2027, and have your year-end package ready in February so the return can be prepared. Partnership and S corporation returns are due March 15, 2027, and C corporation and individual returns April 15, 2027.
By SF Business Solutions · Our team includes one licensed CPA · 4 sources · Updated September 10, 2026
Key dates for 2026 tax returns
When a deadline falls on a weekend or legal holiday, the IRS treats it as met on the next business day, which is why several 2027 dates below move. Dates are for calendar-year businesses.
| What | Due |
|---|---|
| Fourth-quarter 2026 estimated tax | January 15, 2027 |
| W-2s to employees and the SSA | February 1, 2027 |
| 1099-NECs to recipients and the IRS | February 1, 2027 |
| Form 1065 (partnerships) and 1120-S (S corporations) | March 15, 2027 |
| Form 1040 (individuals) and 1120 (C corporations) | April 15, 2027 |
| Extended 1065 and 1120-S | September 15, 2027 |
| Extended 1040 and 1120 | October 15, 2027 |
December and early January: close the year
The return can only be as good as the books behind it. Before anything else:
- Reconcile every bank, credit card and loan account through December 31
- Clear uncategorized transactions and the ask-my-accountant account
- Review unpaid invoices and bills, and write off what will not be collected
- Count inventory at year end if you carry stock
- Record equipment and vehicle purchases so depreciation can be worked out
- Confirm owner contributions and draws, or S corporation distributions
January: the forms
These go out before your own return is even started:
- Check W-9s and send a 1099-NEC to every payee you paid $2,000 or more in 2026
- Issue W-2s and file them with the SSA
- Make the fourth-quarter estimated payment if you pay estimates
- File your fourth-quarter payroll returns through your payroll provider
What your tax return is prepared from
Hand this over in one go and the preparer can start straight away:
- Profit and loss statement and balance sheet for 2026
- The general ledger, or access to your QuickBooks Online or Xero file
- December statements for every bank, card and loan account
- A list of assets bought or sold during the year
- Annual payroll reports and copies of 1099s you issued and received
- Last year's tax return, if they did not prepare it
Working with SF Business Solutions
With monthly bookkeeping, most of this is done before January starts: we close each month between the 5th and 15th of the following month, depending on when your documents arrive, and we prepare and file your business tax return from the same books, so there is nothing to hand over. Monthly bookkeeping starts at $250 a month. If the books are behind, cleanup starts at $250, depending on how far behind they are.
When are 2026 S corporation returns due?
March 15, 2027 for a calendar-year S corporation, or September 15, 2027 with an extension on Form 7004.
When do I have to send 2026 W-2s and 1099-NECs?
By February 1, 2027. The normal date is January 31, which falls on a Sunday in 2027.
When is the last 2026 estimated tax payment due?
January 15, 2027. The earlier 2026 payments were due April 15, June 15 and September 15, 2026, so if you missed one, pay it as soon as you can to limit the underpayment penalty.
Does an extension give me more time to pay?
No. An extension gives you more time to file, not to pay. Tax owed is still due by the original deadline, or interest and penalties apply.
What should I give my tax preparer?
Your 2026 profit and loss and balance sheet, December statements for every account, an asset list, payroll reports, 1099s issued and received, and last year's return. If SF Business Solutions keeps your books and prepares your return, we already have most of it.
What if my books are not ready?
Get them caught up before you file, or file an extension while they are. SF Business Solutions' cleanup starts at $250, and we can then prepare and file the return.
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