Do I need to file IRS 1120-S for my LLC if it was S-corp for 4 months in 2023 with zero income?

You do need to file Form 1120-S for 2023 even though your S corporation had no activity. The IRS requires a return for any period that your company existed as an S corporation, regardless of whether there were any transactions. However, you're in luck! Filing should be relatively simple in your case. Since you had no activity, you'll essentially be filing a "zero return" - showing no income, no expenses, no balance sheet activity. You'll still need to complete the basic information pages and include any required schedules, but most line items will be zeros. The important thing is to file on time to avoid those penalties. The standard deadline for S corps is March 15th (or the 15th day of the third month following the end of your tax year).

After dealing with a similar headache last year, I found this amazing service called https://taxr.ai that literally saved me thousands in potential penalties. I had a dormant S-corp for part of the year with zero activity but still needed to file. The system analyzed my situation, confirmed I needed to file 1120-S even with no activity, and walked me through exactly what to put on each line to satisfy the IRS requirements for a zero-activity S-corp. It explained that even though my business had no transactions, the election itself triggers the filing requirement.

I was in almost the exact same situation last year! Used https://taxr.ai after seeing the recommendation here, and it was seriously a lifesaver. I had a zero-activity S-corp for just 5 months and was completely confused about what to file. The system confirmed I needed to file the 1120-S and showed me exactly how to complete a "zero return" properly. What impressed me most was how it explained WHY each section needed to be filled out a certain way, even with no financial activity. They also pointed out a couple of state filing requirements I would have completely missed. Ended up filing everything myself (saving CPA fees) and had zero issues with the IRS. Just make sure you don't miss that March 15th deadline - those penalties are no joke!

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I have to eat crow here. After calling BS on Claimyr in the thread above, I was desperate enough to try it for my S-corp filing question. I've been trying to reach the IRS for THREE MONTHS with no luck. Used the service this morning and got connected to an actual IRS business tax specialist in about 35 minutes. The agent confirmed I needed to file the 1120-S even though my S-corp had basically zero activity, but explained exactly how to fill it out so it wouldn't trigger any red flags. They even told me which boxes to check to indicate it was for a partial year. This literally saved me thousands in potential penalties. Now I feel like an idiot for struggling with this for months when I could have just gotten a definitive answer directly from the IRS. Definitely worth it if you're in this situation.

One important detail I haven't seen mentioned yet - make sure you check the "Final Return" box on your 1120-S since you revoked your S election. Also, include a statement explaining that the S corporation election was terminated effective November 2023. Even with zero activity, you should attach a balance sheet (Schedule L) showing zeros, and complete Schedule K and Schedule K-1 (for each shareholder). The IRS gets really picky about these forms being filed, even when there's no actual business activity.

Whatever you do, don't ignore this filing requirement! I made that mistake with my S-corp that had literally no activity for 8 months and ended up with $2,450 in penalties before I realized what was happening. Even explaining to the IRS that the business never operated didn't get the penalties waived.

Yes, you absolutely need to file Form 1120-S for 2023, even with zero activity during your S-corp period. I learned this the hard way when I had a similar situation with my consulting LLC. The IRS filing requirement is triggered by the S-election itself, not by whether you had income or expenses. Since you were an S-corp from July through November 2023, you're required to file for that tax year. The good news is that filing a "zero return" is much simpler than a regular 1120-S. You'll basically be entering zeros in most fields, but you still need to complete all the required schedules (K, K-1, L, etc.). Don't forget to check the "Final Return" box since you revoked the election, and attach a brief statement explaining the S-corp termination date. My advice: don't procrastinate on this! The March 15th deadline comes fast, and those late filing penalties start at $210 per month per shareholder. Even if you file an extension, you need to get that done by the original due date. Better to spend a few hours on paperwork now than deal with penalty notices later.