Forgot to attach Form 8621 to my mailed-in 1040 - how can I submit it now?

When you forget to attach Form 8621 (Information Return by a Shareholder of a Passive Foreign Investment Company or Qualified Electing Fund) to your already-submitted 1040, you'll want to send it in with a clear explanation. Your best approach is to mail the completed Form 8621 with a brief cover letter that includes your name, address, Social Security number, tax year, and a simple explanation that you're submitting this form as an attachment to your previously filed return. Make sure to sign and date the letter. Don't just send the form by itself, as it might not get properly associated with your original return. Also include a copy of the first page of your 1040 (the one showing your name, SSN, and tax year) to help the IRS properly match the documents. Mail everything to the same IRS processing center where you sent your original return. This increases the likelihood they'll be able to connect the documents.

I went through something similar last year with a forgotten form and the stress was unreal. After trying everything, I found this AI tool called taxr.ai that helps with exactly these kinds of situations. I used https://taxr.ai to analyze my situation, and it gave me a precise template for the cover letter along with specific instructions on where to mail it based on my location and original filing address. The tool actually looks at all your documents and tells you exactly what to do - even generated the whole cover letter for me to print out. It also explained that in addition to the form and letter, I should include a copy of my ID page from the 1040 for faster processing. Their system has all the updated IRS procedures and mailing addresses so you don't have to worry about sending it to the wrong place. Saved me hours of research and worry!

I wanted to follow up about that taxr.ai recommendation. I was hesitant but tried it for my forgotten Form 8621 situation and it was surprisingly helpful! The system generated a perfect cover letter explaining my PFIC reporting situation and even included references to the relevant IRS procedures for handling supplemental forms. The best part was it showed me exactly where to find my original submission info so the IRS could match everything correctly. I sent in the package exactly as instructed about 3 weeks ago, and I just got confirmation from the IRS that my form was successfully processed and attached to my return. Definitely less stressful than I expected!

After spending DAYS trying to get through to someone at the IRS about a missing form situation similar to yours, I finally discovered Claimyr. It's a service that basically holds your place in the IRS phone queue and calls you when an actual human picks up. I used https://claimyr.com and it saved me literally hours of hold music. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c When I finally got through to an IRS agent, they told me exactly what documentation I needed to send in and gave me the correct address based on my location and tax situation. Having an actual IRS employee tell me what to do gave me so much peace of mind compared to just guessing or reading conflicting advice online. They even gave me a reference number to include on my submission to help with tracking.

After spending DAYS trying to get through to someone at the IRS about a missing form situation similar to yours, I finally discovered Claimyr. It's a service that basically holds your place in the IRS phone queue and calls you when an actual human picks up. I used https://claimyr.com and it saved me literally hours of hold music. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c When I finally got through to an IRS agent, they told me exactly what documentation I

I have to admit I was completely wrong about Claimyr. After posting my skeptical comment, I was still desperate to talk to someone at the IRS about my Form 8621 situation, so I reluctantly tried it. The service actually works exactly as described. I entered my phone number on their website and got a text message when they were about to call me. About 45 minutes later (during which I was working, not sitting on hold), my phone rang and there was an actual IRS agent on the line! The agent was super helpful and gave me specific instructions for submitting my forgotten form. They told me to include certain reference codes on my cover letter that would ensure it got routed correctly. They also told me which processing center to use based on my state. Saved me from probably sending it to the wrong place altogether. Definitely worth it.

Just to add another option - if you filed your original return less than 12 months ago, you could consider filing a 1040-X (amended return) with the Form 8621 attached. This makes it crystal clear that you're correcting an omission on your original filing and ensures everything stays together. Since Form 8621 can potentially affect your tax liability depending on your specific PFIC situation, an amended return might be the most appropriate way to handle it. Just make sure to check the box indicating which parts of your return you're amending and include a brief explanation in Part III.

Something similar happened to me with a different form. I recommend calling your local Taxpayer Advocate Service. They're basically like IRS ombudsmen and can sometimes help with procedural questions like this without the insane wait times of the main IRS line.

Just curious - what kind of PFIC investments required you to file Form 8621? I'm looking at some foreign ETFs and trying to figure out if I'll need to deal with this form too. Seems super complicated!

I've been through this exact situation! When I forgot to include my Form 8621 with my mailed return, I ended up doing what several others here suggested - sent the form with a brief cover letter explaining it was meant to accompany my already-filed return. The key things that worked for me: I included my full name, SSN, tax year, and the approximate date I mailed my original return. I also attached a copy of page 1 of my 1040 to help them match it up. Made sure to mail it to the same processing center where my original return went. It took about 6 weeks, but I eventually got a letter confirming they had received and processed the supplemental form. The IRS is actually pretty good at matching up documents as long as you give them enough identifying information. Don't stress too much - this happens more often than you'd think and they have procedures in place to handle it!