While personal and most corporate taxes are due each year on April 15, the S-Corp is a notable exception. I suppose the IRS probably wanted to stagger the paperwork a bit and so they chose the S-Corp to file a little early, figuring it would cause the least amount of burden on taxpayers since the S-Corp isn’t taxed at the federal level. Thus you won’t actually owe any federal taxes for your S-Corp, but the filing date is a month earlier on March 15 (or the first business day after if the 15th falls on a weekend).
Despite the lack of financial pressure you may still have cause to want to delay your filing. This year I found myself still waiting on some ordered paperwork from the IRS (not everything is online yet) and an extension was needed. Luckily the IRS pretty much “rubber-stamp” approves extensions unless there are serious flags on your company so feel free to take advantage of it if needed. They won’t send you an approval letter so don’t expect one – they only send a letter if you’ve been denied.
The Federal Extension
To file your federal extension you’ll need to fill out the appropriate form, 7004, and mail it in to the right IRS address. The form itself can be found on their website here: https://www.irs.gov/pub/irs-pdf/f7004.pdf. It’s super simple to fill out so I’ll just show you a picture of mine.

Your company information and identifying number (your FEIN or Federal Employer Identification Number) are of course required, and then you simply have to enter the code for your tax return in line 1 and your application fiscal year on 5a. For line 1 just find your tax form, 1120S for S-Corps, and the corresponding code for it on the right, 25. For line 5a enter the calendar year or the start and end date. (It’s probably not necessary to fill both in as I did above but I did it anyway to be clear.)
You don’t even have to sign it, but you do have to mail it of course. You can find the right address in the instructions here: https://www.irs.gov/pub/irs-pdf/i7004.pdf
The State Extension – California
That takes care of the federal extension, but you may have to file one in your state as well so head over to your state’s version of the Franchise Tax Board for information. In California an extension is automatic if you file the federal, but (and this is a big one!) the payment of any taxes due must be paid by March 15 just like normal.
Yes I said that S-Corps aren’t taxed at the federal level but you’ll need to check your state to see if they require any. To my dismay California does, so if I want to avoid penalties, which I do, I’ll need to pay that by the 15th regardless. That means that even though I can’t file my federal taxes yet (remember I’m waiting on some paperwork) I still have to do my taxes so I know what to pay California. If you can’t do that then just approximate as closely as you can, remembering that low-balling will incur penalties and overpayments will trigger a refund once your return is filed.
Turns out California has either a paper process (https://www.ftb.ca.gov/forms/2022/2022-3539.pdf) or an online payment system at https://webapp.ftb.ca.gov/webpay/login/belogin?Submit=Use+Web+Pay+business.
Now normally I would do a screen by screen tutorial on the web pay version, but it’s honestly so easy that I’m just certain if you’ve come this far through my tutorials that you can figure it out. Instead I’m just going to show the paper form below with a tax burden of $1000 as an example. The link above includes the address where you’ll need to mail it and all instructions.

Remember if you choose to file and pay online, which I do recommend, do NOT fill out a paper version and mail it. The online submittal is enough.
That’s pretty much it. If you just can’t get your final taxes completed in time for the March 15 deadline the extension process is pretty simple. Go ahead and take advantage of it!