The small business tax and bookkeeping year, month by month

This page is general information, not advice for your business. The dates come from the IRS 2026 tax calendars and the Texas Comptroller. In other years the same events fall on the same calendar dates, but weekends move them. Check the official page before you rely on a date.

What does a small business tax year look like?

It runs in a loop of four jobs: keep the books each month, pay tax in installments, report payroll each quarter, and file returns once a year. The jobs repeat. Most missed deadlines come from a missing step before the due date, not from the due date itself.

The table below gives the year at a glance. Each month is explained in the sections that follow.

What happens in January?

January is the busiest month for paperwork. Individuals, including sole proprietors, partners and S corporation shareholders, pay the fourth installment of the prior year’s estimated tax around January 15. Employers send Form W-2 to employees. Payers send Form 1099-NEC to contractors, and the IRS calendar lists it with the filing due date for nonemployee compensation paid in the prior year.

Texas sales tax is due on the 20th. Yearly filers report in January for the whole prior year. Quarterly filers report the fourth quarter. Form 941 for the fourth quarter is also due at the end of the month.

For bookkeeping, close the prior year. Match the bank statements to the books, and ask for any missing receipts. Collect a Form W-9 from each contractor before you pay them, not in January. A missing W-9 in January slows down every Form 1099-NEC. Dates in 2026 moved a few days because January 31 fell on a Saturday.

When are the March and April deadlines?

S corporation and partnership returns come first. The IRS 2026 calendar lists March 16 for partnerships to file Form 1065 and furnish a copy of the K-1 to each partner, because March 15 was a Sunday. The S corporation return, Form 1120-S, uses the same date. An S corporation owner needs the K-1 to finish a personal return.

April 15 is the due date for individual returns and for C corporation returns. It is also the first estimated tax installment for the new year. Employers file Form 941 for the first quarter by April 30. Texas quarterly sales tax filers report for January through March on April 20.

An extension changes the date to file. It does not change the date to pay. The IRS says it directly: “The extension is only for filing your return.” If you expect to owe tax, pay an estimate with your extension request. The glossary explains a tax extension in plain terms.

What is due in May and June?

May 15 is the Texas franchise tax report. The Comptroller states that “The annual franchise tax report is due May 15.” Entities at or below the no tax due threshold still file an information report. If you cannot file by May 15, the extended due date is November 15. See the Texas business taxes guide for the franchise tax, sales tax and property tax together.

June 15 is the second estimated payment. The IRS 2026 calendar lists it as “Pay the second installment of 2026 estimated tax.” The payment dates are not evenly spaced, so the gap between April 15 and June 15 is only two months. Revisit your estimate in May so the June payment rests on real numbers.

For the books, May and June are good months for a mid-year review. Compare the profit and loss statement to your plan. If profit is well above last year, your estimates may be too low.

What is due in the summer and fall?

Summer is quiet for returns and busy for payroll. Form 941 for the second quarter is due at the end of July. Texas quarterly sales tax for April through June is due July 20. Use the summer to fix anything the first half exposed.

September 15 brings two events. It is the third estimated payment, and it is the extended due date for S corporation and partnership returns if the owner requested six more months. The extension for those entities uses Form 7004.

October 15 is the last date for individuals who filed an extension. The IRS calendar lists it as the day to “File Form 1040 if you timely requested a 6-month extension.” Form 941 for the third quarter is due at the end of October. November 15 is the extended Texas franchise tax date.

What should a small business do in December?

December is the last chance to change the tax year. Most deductions need to happen in the tax year to count. A purchase made in January belongs to the next year. Corporations make their fourth estimated payment in December. Individuals make the fourth payment in January.

Think about three things in December: income you can defer to next year, expenses that are real needs, and the payroll you must run before the year ends. Do not buy equipment only for the deduction. A deduction reduces tax by a share of the cost, not by the whole cost.

On the books side, count inventory, review fixed assets, and list unpaid bills and unpaid invoices. A CPA needs those lists for the return. They are also a good guide to cash needs in the new year.

How do estimated taxes work for a business owner?

An owner who expects to owe tax pays during the year instead of at filing. The IRS states: “If you are in business for yourself, you generally need to make estimated tax payments.” Estimated tax pays income tax and also self-employment tax.

The usual installments are April 15, June 15, September 15 and January 15. They are not “quarterly” in the strict sense because the periods are uneven. The glossary page on estimated tax payments gives the plain definition and the link to Form 1040-ES.

The IRS can charge a penalty if you pay too little or pay late. Safe harbor rules can protect you if you pay a set share of last year’s tax or of this year’s tax. Those rules depend on your income. Ask a CPA to check them with your numbers.

What is the monthly bookkeeping routine?

A monthly routine takes the same steps each month, so no deadline needs a special effort. A short list works.

1. Record every sale and every expense for the month.
2. Match each bank and card account to its statement.
3. Move sales tax collected and payroll tax withheld into a separate account.
4. Check unpaid invoices and bills.
5. Read the profit and loss statement and the balance sheet.
6. Save a copy of the month’s reports.

The routine takes less time than a yearly rescue. For a longer version with notes, read the small business bookkeeping routine. If you want the work done for you, the small business accounting service page lists what Wallace CPA, PLLC offers.

How do I keep these dates from slipping?

Use one calendar and one owner for it. Enter each due date two weeks early, with the form name. Tie each date to a task in the books. Then review the list each quarter.

Our tax due dates page lists the federal and Texas dates in one place. The IRS and Comptroller pages stay the final source, so check them each January and each April. Dates, thresholds and rates change from year to year.

What documents should I gather before each filing?

Gather documents early, and the filing is a short task. The list changes by deadline, but a core set repeats.

1. Year-end bank and card statements for every business account.
2. A profit and loss statement and a balance sheet from your books.
3. Payroll reports, including quarterly Form 941 copies and each Form W-2.
4. Forms 1099 you received, plus a list of contractors you paid and their W-9 forms.
5. Loan statements, with the interest paid and the balance at year end.
6. A list of equipment bought or sold during the year, with dates and costs.
7. Your Secretary of State papers and EIN letter, for any Texas filing.

Send the set to your CPA before the due date, not on it. A late package forces a rushed return, and rushed returns miss deductions.

What if I miss a date?

File and pay as soon as you can. The cost of a missed date grows with time, because penalties and interest build. Do not wait for a perfect set of records. File with what you have, then amend if needed.

Penalties can sometimes be reduced. A first mistake, a good history and a quick fix all matter to the agency. Ask a CPA what relief may apply to your case. No one can promise that a penalty will be removed. If you got a Comptroller or IRS notice about a missed date, answer it by the date shown on the notice.

How do payroll and sales tax fit into the monthly routine?

They fit as a fixed step in the monthly close, not as a surprise at the deadline. When you run payroll, move the withheld tax and the employer share into a separate account. When you record a sale, track the sales tax collected as a liability, not as income. Then each report is a simple transfer from a balance you already hold.

A business with employees also checks that every deposit matched its schedule. The IRS tells monthly and semiweekly depositors apart by the size of their tax liability. Your payroll provider or CPA can confirm which schedule applies to you. See the payroll service page for the work Wallace CPA, PLLC lists for payroll.

Next step

To go over your own calendar, read about small business accounting, call Wallace CPA, PLLC at (877) 682-1171, or use the contact form. This page is general information. Talk to a CPA about your own situation before you rely on any date or amount.