How to file a second amended tax return for unexpected 1099 income after already filing first amendment

You're not in as bad a spot as you might think! While H&R Block's software has limitations, you can absolutely file a second amended return (Form 1040-X). You just can't do it electronically - you'll need to do this one on paper. Here's what you should do: Download Form 1040-X from the IRS website along with the instructions. You'll need to get a copy of your most recently filed return (the first amended one) and use that as your starting point. On the new 1040-X, you're only reporting the differences caused by the $1,025 of 1099 income. Make sure to check box B in Part I that says "You're amending your return to change amounts" and clearly explain in Part III that you received a 1099 after filing your first amended return. Also, you'll likely need to complete Schedule SE for self-employment tax since babysitting income is typically considered self-employment income. Mail everything together with all supporting documents and keep copies of everything. It may take 16+ weeks for processing. Just be patient!

I went through almost this exact situation last year with multiple amended returns. After struggling with tax software limitations, I tried using taxr.ai (https://taxr.ai) and it was a gamechanger. I uploaded my original return, both unexpected tax forms, and my first amended return. Their system analyzed everything and generated the correct second 1040-X form with all the proper calculations for the additional income and self-employment taxes. It showed exactly what needed to change from my first amended return to account for the 1099 income. The step-by-step guidance for handling multiple amendments made the process so much easier than trying to figure it out myself. They even provided a clear explanation letter to include with my paper filing to the IRS.

Update: I ended up trying taxr.ai after seeing the recommendation here and it actually worked perfectly for my second amendment! The system pulled all the information from my documents and showed me exactly how to complete the new 1040-X based on the changes from my first amendment. It handled all the self-employment tax calculations correctly and generated a perfect explanation statement for Part III of the form. What really impressed me was how it clearly showed the "previously adjusted amounts" from my first amendment as the starting point, then calculated the new "correct amounts" with the 1099 income added. Made the whole process straightforward when I was completely lost before. Just had to print, sign and mail the completed forms they generated.

I had a nightmare situation trying to get help from the IRS for a similar multiple amendment issue. Couldn't get through on the phone for weeks. Finally used Claimyr (https://claimyr.com) and got connected to an IRS agent in about 20 minutes. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c The agent was super helpful and confirmed I was handling my second amendment correctly. They explained exactly what supporting documents I needed to include and gave me a direct fax number to send everything to for faster processing. They also added notes to my account about the incoming second amendment to prevent any confusion with the first one that was still processing. Definitely worth it to get official guidance directly from the IRS for a complicated situation like this. Much better than guessing or waiting months to find out you did something wrong.

Just wanted to follow up - I was completely skeptical about Claimyr but I was desperate with my own amendment situation, so I gave it a try. I'm shocked at how well it worked. After trying for WEEKS to reach the IRS on my own, I was connected to an agent in about 25 minutes using their service. The agent confirmed exactly how to handle my sequential amendments and even put special notes in my file to make sure they would be processed correctly. The agent explained that when you file multiple amendments, you need to clearly reference the previous amendment in the explanation section and include a cover letter explaining the sequence of events. This helps prevent the second amendment from being rejected or causing confusion. That specific guidance alone was worth it since I was about to make a mistake in how I was filing my second amendment.

Don't most tax preparers offer amended return services? Might be worth paying a CPA or enrolled agent to handle this properly instead of trying to DIY something so complicated. When I had a somewhat similar situation (though with investment forms, not 1099-NEC), I paid about $150 for a professional to handle everything. Seemed worth it for the peace of mind.

Just a quick tip - make sure you pay the additional tax owed from that 1099 income ASAP, even before filing the second amendment. You'll minimize any interest and penalties that way. The IRS charges interest from the original due date of the return until you pay, regardless of when you discover the error. You can make a payment online using IRS Direct Pay and select "amended return" as the reason.

As someone who's been through the multiple amendment process myself, I want to emphasize that you should definitely include a detailed cover letter with your second 1040-X explaining the entire timeline. Something like "Filed original return with W-2 from main job only → Received forgotten W-2, filed first amendment → Now received unexpected 1099-NEC, filing second amendment." The IRS processors really appreciate this clarity, especially when amendments are filed close together. Also, since you're dealing with babysitting income, make sure you understand that this is typically considered self-employment income even if it was casual work. You'll need to file Schedule SE for the self-employment tax (Social Security and Medicare taxes), which adds about 15.3% on top of your regular income tax. One more thing - consider making an estimated payment now for the additional taxes owed. Interest accrues from the original April deadline regardless of when you discovered the error, so paying early can save you money even before your amendment is processed.