Which day is yours
Business Tax Deadline. The company's tax election picks the day.
A partnership and an S corporation land in March. A C corporation lands in April. An LLC follows the election on its letter. This practice closes the month under that date before the return is prepared. Steven Palmieri is the Tax CFO on the file, and the practice also calls that role the Entrepreneur's CFO.
How is your company taxed?
Name the election. Write the word missing when the letter is not in the file. A missing letter is a better start than a guessed day.
You will be talking to the Steven Palmieri practice.
The Tax CFO way.
A preparer can file whatever arrived by the due day. A Tax CFO closes the months all year, so the due day is when a finished return goes out, and October is when the year's decisions still get made.
The company date, the month under that date, and the choice still open in October are three different jobs. We keep them on one page, and we do not let the due day pretend the month is finished.
Click to read the March Monday ›Tap to read the March Monday ›The March Monday
The March Monday still arrives on 16 March 2026, and the month under it still has to close. At the kitchen table the notice sits on one side and the bank page sits on the other. Neither page moves the Monday.
Click to see the K-1 date ›Tap to see the K-1 date ›The K-1 follows
An S corporation shares that Monday. The K-1 cannot leave until the company month under it is actually closed.
Click to open the April date ›Tap to open the April date ›The April Wednesday
A calendar-year C corporation files on 15 April 2026, a Wednesday, and that row is not the March row.
Click to check the LLC letter ›Tap to check the LLC letter ›Read the letter first
A disregarded company follows the owner. Any other letter follows the election written on it, not the nickname people use.
Click to see the other dates ›Tap to see the other dates ›Estimates are not the filing day
Estimated tax for an owner who also has a company falls in April, June, September, and the January after the year. Those months are not the company filing day. A figure is still a guess until the month agrees with the bank.
Click to picture an open February ›Tap to picture an open February ›When February was open
Picture a March Monday that arrived with February still open. The K-1 guessed, and both personal returns sat still. No real company sits behind that picture.
Six dates, then the month under them
The week a payroll runs is the week the shop stays open late and the back room stays lit after the door is locked. We know that week. The lights do not file the wage report. The provider you already run does, and we only build the file.
Six dates worth opening
Open a month. The line under it is the date we watch with you.
1March
Partnership and S corporation years that follow the calendar land on Monday 16 March 2026, because the 15th falls on a Sunday.
We close the month under that Monday before anyone treats the return as ready to leave.
2April
A C corporation on a calendar year lands on Wednesday 15 April 2026.
We keep that Wednesday apart from the March companies, even when the personal date shares the same Wednesday.
3May
May is already too late to ask for the March extension. Form 7004 has to reach the IRS before the original due day, and an extension is not a payment.
We name that limit out loud. A request filed after the Monday does not move the Monday, and tax already due does not ride along.
4June
June is an estimate month for an owner who also has a company. The dollar figure stays in Publication 505.
We ask whether a closed month can support a real figure before anyone talks about a payment.
5September
September is another estimate month. October is still early enough to change the shape of the year.
We use that window for a decision, and we do not promise that money comes back.
6January
The estimate after the year falls in January. Form 941 for the last quarter is due by the last day of that month.
The payroll provider you already run still files the wage report. We set the file up and we do not run payday.
Click to meet the practice ›Tap to meet the practice ›
Steven Palmieri, Tax CFO
The Entrepreneur's CFO. October can still change a year that has not ended, and the date on the chart is useful only when the month under it has already closed.
The practice is in Dallas. Owners meet us by video, with the books on a shared screen and a calendar link, while the month still closes on its named day.
Bring the month under that day
You will be talking to the Steven Palmieri practice.
The rest of the year, one tap down
The cards above are the short version. The dates, the charges, and the month under them stay here for the owner who wants the whole argument.
Four letters, then a day
Owners ask for one day. The useful first question is the letter in the file. A calendar-year partnership files in March. So does an S corporation, and the K-1 follows that filing. A calendar-year C corporation files in April. A disregarded company follows the owner's own date.
The nickname on the bank account is a weak source. People say LLC and then stop, as if the letters themselves picked a month. They do not. The election on the letter picks the month, and a missing letter is an honest answer we would rather hear on the first call than after a return is built on the wrong row.
IRS Publication 509 is the table for the weekend rule. A due day that lands on a weekend moves to the next business day.
What 2026 does to the printed day
15 March 2026 is a Sunday. The partnership return and the S corporation return move to Monday 16 March 2026. 15 April 2026 is a Wednesday, so the C corporation date stays put. Older charts that still show the 15th for March will send an owner to a closed office.
The Monday is only useful when the month under it is closed. A return built on an open February is a guess with a cover sheet. We would rather say the month is open than pretend the K-1 is finished.
Estimates, the May report, and payday
Estimated tax for an owner who also has a company generally falls in April, June, September, and the January after the year. Those dates are not the company filing date. Mixing them is how a quarterly payment gets called the whole year.
IRS Publication 505 is where the estimate math lives. The safe-harbor arithmetic stays in that publication and is not copied onto this site.
Form 7004 is a request for more time to file, and it is not a payment. For a partnership or an S corporation it can move the March Monday to 15 September. For a C corporation it can move the April Wednesday to 15 October. The request has to reach the IRS before the original due day, so May is already too late for a March company. Tax that was already due does not ride along. Publication 509 is the weekend table. This page does not restate a penalty table.
Form 7004 moves Form 1065 and Form 1120-S from the March Monday to 15 September, and Form 1120 from the April Wednesday to 15 October, when the request reaches the IRS before the original due day. The tax already due does not ride along.
Payday keeps its own dates even when another company runs the checks. The wage report follows the quarter by a full month and lands on that month's last day. The money that goes with those wages stays with the company already paying people. We can build the file they file from. We never press the payday button ourselves.
Form 941 closes on the final day of the month that follows the quarter. The wage deposits that travel with it stay on the payroll company already running payday.
The month under the date
A date with an open month under it is a circled day on a chart. The bank has not agreed. A pile of costs with no home is a sign the month is not closed. We map the accounts to the lines the return will need, and we stop when a month will not tie.
The relief people feel is ordinary. The Monday stops being a rumor. February has a last page. The K-1 can leave. That is the work, said in a sentence a person can repeat.
If the day already passed
File the company return next. Waiting for a perfect month makes the filing charge and the payment charge both grow, and those two charges are different. The IRS page on failure to file lists the shape of the filing charge, including a per-partner amount for a partnership, and this page does not restate it.
A request to remove a penalty is a separate matter. We do not represent you before the IRS. If that is the need, we say so and step aside. What we can still do is put the books in order so the return itself can be prepared.
A letter about cancelled debt is a different letter from a late-filing notice. Publication 4681 has the worksheet for whether that amount is taxed. We do not run that worksheet on a public page.
What to bring to the first call
Bring the letter that says how the company is taxed, or say the letter is missing. Bring the month you last trusted. The drawer beyond those two can wait until the call names a page.
October can still change a year that has not ended. Owner pay, an estimate, and the shape of the entity, when it needs a conversation, still have time. October is when we have that conversation, while the company date is still months away and no return has locked the year. Nobody should read it as money coming back. The useful thing under the date is a closed month.