I went through this exact same situation with Form 3531 about 6 months ago! The signature issue is incredibly common - even when you think you signed everything properly, sometimes the ink doesn't show up clearly when they scan it, or you might have missed signing a schedule attachment. For the address situation, I was confused about this too until I called the IRS. They explained that even though you moved after filing, they want your return to reflect your current address in their system so all future correspondence about that specific tax year goes to the right place. It's more of an administrative update than anything punitive. You have a couple good options here: 1) Fix the paper forms and mail them back (your February filing date is preserved), or 2) E-file instead since your paper return was technically rejected. I went with e-filing and it was SO much faster - got my refund in about 2 weeks instead of waiting months for paper processing. If you do e-file, just use your current address from when you moved in July. Since you already updated your address with the IRS online, this will actually solve both the signature and address issues at once. The electronic signature takes care of the signing problem, and having your current address on the return matches their records. Don't stress too much - this is a very fixable situation and won't affect your refund timeline as long as you respond promptly!

I've been following this thread closely since I'm dealing with a very similar Form 3531 situation right now! Thank you to everyone who shared their experiences - it's been incredibly helpful to see so many people who went through the exact same thing. Based on all the advice here, I'm convinced that e-filing is the way to go. The idea of getting my refund in 2-3 weeks instead of potentially waiting months for paper processing is really appealing, especially since I've already been waiting since February like the original poster. One thing I want to emphasize for anyone else reading this thread: make sure you're using black ink if you do decide to go the paper correction route. I learned this the hard way on a different form last year - apparently blue ink sometimes doesn't scan clearly in their systems, which can trigger the signature issue even when you think you signed everything properly. The address situation still seems confusing to me though. If I moved after filing but before receiving the Form 3531, should I use my old address (from when I originally filed) or my current address when e-filing? I've seen conflicting advice on this point.

Has anyone actually calculated how much this "double taxation" costs us? I make about $85k and pay roughly $6500 in FICA taxes. If I could deduct that amount, at my tax bracket (22%), that would save me $1430 per year. That's significant money!

I completely understand your frustration - this has bothered me for years too! What helped me wrap my head around it is realizing that payroll taxes and income taxes serve fundamentally different purposes, even though they both come out of our paychecks. The key insight is that payroll taxes are more like mandatory insurance premiums than traditional taxes. You're not just paying the government - you're earning credits toward future Social Security benefits and Medicare coverage. The amount you eventually receive in benefits is directly tied to how much you paid in over your working years. If payroll taxes were deductible, it would essentially mean getting a tax break on money that's going into an account with your name on it (even if it's administered by the government). That's why they're treated separately from income taxes, which fund general government operations you may never directly benefit from. That said, I totally get why it feels unfair when you're looking at your paycheck! The lack of immediate tax benefit definitely stings, especially when you're already dealing with income tax on top of it.

PSA: These codes can change during processing! Don't panic if yours switches - totally normal in 2025 with the new AI processing system they implemented

This is super helpful! I've been checking my WMR obsessively and my cycle code is 20250302 - so if I'm reading this right, I'm on daily updates? Still waiting for my 846 code to show up but at least now I know what to expect. Thanks for breaking this down in simple terms! 🙏

I went through this exact same situation last year and can definitely put your mind at ease! You should absolutely still receive your full $1,300 refund. The CP23 notice is completely separate from your current tax return refund. Think of it this way - the CP23 was addressing a debt from your previous tax period (the underpaid estimated taxes from your DoorDash work), while your refund is money the government owes YOU from your current tax return. Since you already paid the $780 from the CP23, that matter is completely resolved. The IRS won't reduce your current refund to pay a debt that's already been paid. These are processed as entirely separate transactions in their system. The only thing you might experience is a slight delay (maybe 1-2 extra weeks) in receiving your refund while they update your account records to show the CP23 payment has been processed. I was in your exact shoes last year - got a CP23 for some freelance income I messed up on, paid it immediately, then spent weeks worrying about my refund. Got every penny of my refund about 3 weeks later. You should be all set!

I just went through this exact situation a few months ago! Got a CP23 notice for underpaid estimated taxes from some freelance work I did, and I was absolutely panicking about how it would affect my refund. Here's what happened in my case: I paid the CP23 amount immediately (just like you did), and I still received my full refund exactly as calculated on my return. The two are completely separate - the CP23 addresses a previous tax period's underpayment, while your refund is from your current filing year. The only thing I noticed was that my refund took about 2-3 weeks longer than normal to process. The IRS had to update my account to reflect the CP23 payment before releasing my refund, but once that was done, I got every penny I was expecting. Keep checking the "Where's My Refund" tool - if it shows "being processed" for longer than usual, that's totally normal in this situation. Since you already cleared the $780 debt, there's no reason they would reduce your $1,300 refund. You should be getting the full amount soon!

in the same boat rn...system is so broken

This happened to me twice last year! Both times it was a processing error at their mail facility. I called the Michigan Treasury Department directly (since this was from them, not the IRS) and they were actually pretty helpful. They resent the document within a week. Don't panic - it's usually just a clerical error, but definitely follow up to make sure you don't miss any important deadlines!