S-corp payroll calendar: every deadline in the year

When you run payroll yourself, you have to track the deadlines too. Most missed payroll deadlines come from not knowing a date was coming. This guide lists the federal dates for a small S corporation, plus the Oklahoma dates for state withholding and unemployment.

One note before you start. The IRS calendar in Publication 15 lists dates that "haven't been adjusted for Saturdays, Sundays, and legal holidays" (IRS Publication 15). If a filing or deposit date lands on a weekend or legal holiday, you may file or deposit on the next business day (IRS employment tax due dates).

Every payday: federal tax deposits

Your federal income tax withholding, Social Security tax and Medicare tax get deposited on a schedule, not just once a quarter. The IRS has two deposit schedules: monthly and semiweekly (IRS employment tax due dates).

Monthly depositor: deposit taxes on payments made during a month by the 15th day of the following month.
Semiweekly depositor: for payments made Wednesday, Thursday or Friday, deposit by the following Wednesday. For payments made Saturday, Sunday, Monday or Tuesday, deposit by the following Friday.
Next-day rule: if you build up $100,000 or more in taxes on any day during a deposit period, deposit by the next business day.

Federal tax deposits must be made by electronic funds transfer. The government's Electronic Federal Tax Payment System (EFTPS) is free. You can also pay through your IRS business tax account or Direct Pay for businesses. Our guide on how to make an EFTPS payroll tax deposit covers the steps.

Making a deposit does not count as filing your return. You still have to file Form 941 each quarter.

Not sure which schedule applies to you? Read payroll tax deposit schedules: monthly vs. semiweekly.

Every quarter: Form 941 and FUTA

Form 941 is due by the last day of the month after each quarter ends:

Quarter	Months	Form 941 due
1st	January to March	April 30
2nd	April to June	July 31
3rd	July to September	October 31
4th	October to December	January 31 (next year)

If you deposited all taxes on time, you get 10 more calendar days to file (IRS employment tax due dates). See how to file Form 941 yourself for a walk-through.

FUTA deposits follow a quarterly test. If your FUTA tax for a quarter is $500 or less, carry it over to the next quarter. Once the amount owed (plus anything carried over) is more than $500, deposit the whole amount by the last day of the month after the quarter ends. That is April 30, July 31, October 31 or January 31. If the fourth-quarter amount is $500 or less, you can deposit it or pay it with Form 940 by January 31 (IRS employment tax due dates; IRS Publication 15). More detail is in Form 940 and FUTA tax: a do-it-yourself guide.

January: the busiest month

January has the most deadlines of the year. These dates come from the 2026 edition of Publication 15 and cover the 2025 tax year (IRS Publication 15).

By January 31:

File Form 941 for the fourth quarter of the previous year. Deposit any income, Social Security and Medicare taxes you have not deposited yet. You may pay these taxes with Form 941 if your total liability for the quarter (Form 941, line 12) is less than $2,500.
File Form 944 instead, but only if the IRS has told you in writing to do so.
File Form 940 for the previous year's FUTA tax.
Give each employee a completed Form W-2. That includes you, since an S-corp owner on payroll is an employee.
File Forms W-2 with Form W-3 with the Social Security Administration.
If you paid contractors, file Form 1099-NEC with the IRS and give a copy to each payee.

By February 10: if you deposited all taxes on time, you may file Forms 941, 940 and 945 by this date instead.

Oklahoma W-2s: employers with Oklahoma withholding had to send W-2 and W-3 information for tax year 2025 to the Oklahoma Tax Commission (OTC) by January 31, 2026. You submit it through OkTAP, either by uploading a file or by entering it by hand. The OTC does not accept paper forms or physical media (Oklahoma Tax Commission, Packet OW-2).

February and March: W-4s and other information returns

By February 15: ask for a new Form W-4 from every employee who claimed exemption from federal income tax withholding last year.
February 16: last year's exempt Forms W-4 expire. If an employee has not given you a new one, withhold as if they checked Single or Married filing separately and made no other entries (IRS Publication 15).
By February 28: file paper Forms 1099 (other than 1099-NEC) with Form 1096.
By March 31: file those same information returns if you file them electronically.

If you file 10 or more information returns in total, counting Forms W-2 and 1099 together, you must file them electronically (IRS employment tax due dates).

Oklahoma withholding deadlines

How often you remit Oklahoma income tax withholding depends on how much you withhold (Oklahoma Tax Commission, Packet OW-2):

$500 or less per quarter: remit quarterly, on or before the 20th day of the month after the quarter closes.
More than $500 but less than $5,000 per quarter: remit monthly, on or before the 20th of the following month.
$5,000 or more per month in the previous fiscal year: you must remit electronically.
An average of $10,000 or more per month in the previous fiscal year: remit on the federal semiweekly schedule. Employers that use the federal semiweekly schedule also remit Oklahoma withholding on that schedule.

Your return reports the number of employees paid in the quarter, total wages, and total Oklahoma tax withheld. For the exact due dates of the return itself, check the current OTC instructions. To set up your account, see OkTAP withholding registration and Form WTH-10001.

Oklahoma unemployment (OES-3) deadlines

Oklahoma state unemployment runs on its own quarterly cycle. You report contributions and wages through the Employer Portal on the Oklahoma Employment Security Commission (OESC) website on or before the last day of the month after each calendar quarter. Paper Form OES-3 is allowed only if the Commission grants an exception (Okla. Admin. Code 240:10-5-91).

Payment is due by the same date. You can pay by ACH debit or credit, wire or EFT, or an accepted credit card. If you mail a check, a $1.50 service fee applies.

If your business first becomes an employer partway through the year, you file OES-3 reports for all earlier periods of that year by the due date for the quarter in which you became an employer. Step-by-step instructions are in Oklahoma OES-3 quarterly unemployment report: how to file with OESC.

Fall and December: get ready for year-end

The months before year-end are when you set up for January.

Register for SSA Business Services Online early. On November 7, 2026, SSA started a new authorization process for BSO Electronic Wage Reporting. A Responsible Entity Officer must register the organization first. The registration code comes by mail and can take 15 to 20 days. SSA says to allow at least 2 weeks to finish registration, well before the January deadline. You sign in with Login.gov or ID.me (SSA Business Services Online; SSA employer information). Our guide on filing W-2s and W-3 through SSA Business Services Online explains the process.
Confirm your deposit schedule. Before each calendar year starts, you must work out whether you are a monthly or semiweekly depositor, based on your lookback period (IRS employment tax due dates).
Decide on Form 944 early in the year. If you think your employment taxes for the year will be $1,000 or less and you want to file one annual Form 944, you must contact the IRS during the first calendar quarter to ask. Keep filing Form 941 until you get written notice from the IRS (IRS Publication 15).
Remind employees about Form W-4. Ask anyone whose withholding needs to change to submit a new one.

For a full list of year-end tasks, use the year-end payroll checklist for small employers.

Quick checklist for each quarter

Federal deposits made on your monthly or semiweekly schedule
Form 941 filed by the last day of the month after the quarter
FUTA deposited if the amount owed is over $500
Oklahoma withholding remitted by the 20th (monthly or quarterly, depending on amount)
OES-3 report filed and paid through the OESC Employer Portal by the last day of the month after the quarter
Next quarter's dates added to your calendar

Where Selfroll fits

Selfroll is a free payroll calculator for small S-corp owners. It does the payroll math, keeps a deadline calendar you can export to .ics, and fills draft copies of Forms 941, 940, W-2, W-3 and Oklahoma WTH-10001. You review and sign the forms, move the money from your own bank, and file everything yourself.

Sources

This guide is general information, not tax or legal advice. Check current IRS, SSA and state rules or ask a CPA.