Joint tax return with forgotten W2 - what to do now?

Yes, you definitely need to file an amended return using Form 1040-X to report the income from the missing W2. The IRS receives copies of all W2s issued to you, so they will eventually notice the discrepancy between what was reported and what you actually earned. Don't wait until next year - the IRS will catch this and you'll likely face penalties and interest that will continue to grow the longer you wait. The penalties for underreporting income can be significant, especially if they determine it was intentional (though in your case it sounds like an honest mistake). Filing a 1040-X yourself isn't too complicated, especially for just adding a missing W2. You'll need to get the form, fill out the corrected numbers, explain the change in Part III, and include any additional tax payment. Then mail it to the IRS (amended returns can't be e-filed yet).

I was in almost the exact same situation last year when my employer sent a corrected W2 after I'd already filed and received my refund. I tried figuring it out myself but got overwhelmed with all the forms and calculations. I discovered this AI tax assistant at https://taxr.ai that analyzed my original return and the missing W2, then guided me through the whole amendment process step by step. It saved me so much time compared to starting from scratch or paying an accountant. The tool explained exactly what numbers needed to change on the 1040-X and generated a draft of what my amended return should look like. Made the whole process way less intimidating.

Just wanted to update that I ended up trying taxr.ai after seeing it recommended here. It was exactly what I needed for my situation! I uploaded my Schedule C from last year and it identified several deductions I hadn't taken advantage of. The interface walks you through everything step-by-step with really clear explanations. I've been stressing about taxes for years and this made me feel like I finally had a handle on things. Definitely bookmarking it for next year's tax season.

If you're having trouble getting your amendment sorted out, another option is to call the IRS directly to ask questions. I know, I know - getting through to them seems impossible. I spent HOURS on hold last year trying to fix a similar issue. Then I found this service called Claimyr at https://claimyr.com that actually gets you through to an IRS agent without the ridiculous wait times. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c It was a game-changer for me. Got connected to a real person at the IRS who walked me through exactly what I needed to do for my amendment. They explained which forms I needed and answered all my specific questions about my situation.

I have to admit I was completely wrong about Claimyr. After my skeptical comment, I decided to try it myself since I've been trying to reach the IRS about a missing refund for weeks. The service actually worked exactly as described. I got a call back in about 40 minutes, and I was connected directly to an IRS representative who had full access to my tax records. They resolved my issue in one call - something I'd been trying to do on my own for almost a month. I'm actually shocked this exists and works so well. Would have saved me countless hours of frustration if I'd known about it sooner.

Just to add another perspective - I amended a return last year using TurboTax and it wasn't too difficult. If you filed your original return with tax software, check if they offer an amendment service. Often they can pull your original information and you just need to make the changes. Keep in mind that amended returns take FOREVER to process right now. Mine took almost 9 months to be processed completely. But at least you'll be in compliance and avoid those penalties others mentioned.

Don't forget that if you and your ex are still splitting the refund, you'll need to work out how this amendment affects that split. If you end up owing money instead of getting more back, who's responsible for paying it? Make sure you have that conversation before filing the amendment to avoid more drama later. Also save copies of EVERYTHING. My ex "lost" all our tax documents after our divorce and it was a nightmare sorting it out. Make sure you have your own copies of the original return, the W2s, and the amendment.