The S-corp election deadline

How the 2 months and 15 days are counted

The IRS doesn't count 75 days. It counts two calendar months, then 15 days, and the two-month period has a precise definition: it starts on the day of the month your tax year begins and ends at the close of the day before the same-numbered day two months later. Then you add 15 days. If your tax year begins January 1, the two months run out at the end of February and the fifteenth day after that is March 15.

The IRS's own instructions carry the examples worth memorising. A company whose first tax year begins January 7 has until March 21. One that begins November 8 has until January 22 of the following year. A calendar-year company that already exists and wants the election for next year can file at any point from January 1 through March 15 of that year — or at any time during the current year, because an election filed during the tax year before the one it's meant for is timely too.

That second window is the one people don't know about. If you're an existing LLC reading this in the second half of 2026 and you want S-corp treatment from January 1, 2027, you don't wait for January. You can file now and the election simply sits until the year starts.

What the 2026 deadline actually is

For a calendar-year company wanting the election to cover the 2026 tax year, the fifteenth day after the two months is Sunday, March 15, 2026. Federal tax law (26 U.S.C. § 7503) treats an act as timely when the last day falls on a Saturday, Sunday or legal holiday and you do it on the next business day, which puts the practical 2026 deadline on Monday, March 16, 2026. In 2027, March 15 is a Monday and the date stays put.

The date is about when the form is faxed, postmarked or received, so keep the fax transmission report or the certified mail receipt. Those two pieces of paper are exactly what the IRS's own acceptance notice tells you to send back if it later thinks you filed late.

If today is after March 16, 2026 and you haven't filed, the choice is between two honest options: file now for a January 1, 2027 effective date, which is simply an on-time election for next year, or file now for 2026 and ask for late-election relief, which is a different filing with its own conditions. Which one is right depends on how you've been paying yourself and filing this year, and that is a CPA conversation, not a filing one.

A new company: the clock starts earlier than you'd think

For a brand-new company the tax year begins on the earliest of three dates: the day it first had shareholders (for an LLC, members), the day it first had assets, or the day it began doing business. In practice that's usually the day the state approved the formation, because the company has an owner from that moment. It's not the day you opened the bank account, and it's not the day the EIN letter arrived.

That last point catches people. Form 2553 needs an EIN, and a new LLC doesn't have one on day one, so the sequence is: state approval, EIN, then Form 2553 — and the two months and 15 days have been running since the first of those. A June 10 formation has a deadline in late August. It's plenty of time if you know the clock is running and none at all if you assumed it started with the EIN.

It's why our LLC-plus-S-corp order files the election immediately after the EIN comes back, and why we tell people forming mid-year to decide the S-corp question before formation rather than after. Nothing stops you electing later — a company formed in June that misses its first-year window can file for January 1 of next year at any point before then — but the first-year election is the one with the short fuse.

The effective date on the form, and what a late filing does to it

Item E on Form 2553 is the date you want the election to take effect. For an existing calendar-year company that's normally January 1 of the election year; for a new company it's the first day of its first tax year. The deadline is measured from that date, not from the day you happen to file, so writing an earlier date doesn't buy anything — it just makes the filing later.

File after the deadline without asking for relief and the law says the election is treated as made for the following tax year (26 U.S.C. § 1362(b)(3)). The IRS's acceptance notice, the CP261, will simply show the later date, with a line saying that because you filed late, the later date is the earliest you can be treated as an S corporation. People file the letter away without reading it and discover the gap at tax time. Read the effective date on the notice against the one you asked for.

One thing that isn't a step: an LLC electing S-corp treatment files Form 2553 alone. Form 8832 is the election to be taxed as a C corporation, and filing it as a warm-up for the S-corp election is a common and expensive mistake.

If you've already missed it

A missed deadline isn't necessarily the end of it. IRS Revenue Procedure 2013-30 lets a company that meant to be an S corporation from a given date, and can show reasonable cause for the late form, ask for the election to be treated as timely — for up to three years and 75 days after the intended effective date. It's the same Form 2553 with a legend across the top and a signed statement explaining the delay, and the IRS charges nothing for it.

It is relief rather than a right, and it exists to fix paperwork that should have been filed, not to let a company decide in hindsight that last year would have been a good S-corp year. We prepare relief requests as part of the same $50 election where the facts support one, and we've written the conditions up separately.

How to file it, and how to prove you did

Form 2553 goes to one of two IRS service centres — Kansas City or Ogden — depending on the state where the company's principal office is, by fax or by mail. There is no e-file route for it. The IRS keeps the current addresses and fax numbers on its Where to File page for Form 2553; check the page rather than a form printed years ago, because the addresses have moved before.

Every shareholder has to sign a consent, and a form with a missing consent isn't a complete election, which is the commonest reason one is rejected. Sign, date, fax, and keep the transmission report with the signed copy — that report is your proof of the filing date if the IRS's records and yours ever disagree.

We prepare the form with the shareholder consents and send it within one business day for $50 flat, and there's no government fee on top because the IRS doesn't charge for the election. If you'd rather do it yourself, the form is short, the instructions are on irs.gov, and the fax number is the only thing you have to look up.

Common questions