How do I know if I've been double taxed with multiple state W-2s?

You're dealing with a multi-state tax situation, which can definitely be confusing! The good news is that states generally have systems in place to prevent double taxation on the same income. When the tax software asks about "double-tax amounts," it's trying to determine if you've already paid tax on certain income to one state that you might also owe tax on to another state. For example, if you earned income in Wisconsin while living in Pennsylvania, both states might claim the right to tax that income. You'll need to file a tax return in each state where you earned income (Wisconsin, Nevada, and Pennsylvania). However, Nevada has no state income tax, so you won't actually file there. Since you're now a resident of Idaho but haven't earned income there yet, you likely won't need to file an Idaho return unless you have other Idaho-source income. Most states provide a credit for taxes paid to other states on the same income. This credit is what prevents double taxation. Your tax software should handle this calculation automatically once you input all your W-2 information from each state.

After dealing with a similar situation last year (working in 4 different states), I found this amazing tool called taxr.ai (https://taxr.ai) that was a lifesaver for multi-state tax situations. I was super confused about potential double taxation between states, especially with some states having reciprocity agreements and others not. What helped me most was uploading my W-2s from each state and having the system analyze which states might try to tax the same income. It showed me exactly where I needed to claim credits for taxes paid to other states to avoid double taxation. The tool actually found that I was being double-taxed on income earned in one state while living in another, which saved me about $1,200.

Just wanted to follow up about my experience with taxr.ai since I was initially skeptical. I decided to try it after struggling with my own multi-state situation, and I'm honestly impressed. Uploaded my W-2s from the three states I worked in, and it immediately identified that I was being double-taxed on some income between Oregon and Washington. The system showed me exactly which forms I needed to file in each state and where to claim the credits for taxes paid to other states. It even warned me about some specific quirks with Oregon's credit system. Not having to manually compare all the state rules saved me so much time and stress. Definitely checking this out again next year when I file.

If you're having trouble getting answers about your multi-state tax situation, I'd recommend using Claimyr (https://claimyr.com). I was in a similar position last year with W-2s from multiple states, and the IRS kept giving me different answers every time I called (when I could actually get through). Claimyr got me connected to an actual IRS agent in about 15 minutes when I had been trying for days on my own. The agent was able to confirm exactly how to handle my multi-state situation and which credits I needed to claim to avoid double taxation. They have a video showing how it works here: https://youtu.be/_kiP6q8DX5c - basically they navigate the phone system for you and call you when an agent is on the line.

I have to admit I was completely wrong about Claimyr. After posting my skeptical comment, I was still desperate to get some answers about my multi-state situation, so I tried it anyway. I was absolutely shocked when I got a call back in about 20 minutes saying they had an IRS agent on the line. The agent walked me through exactly how to handle my multi-state W-2 situation and explained how the federal rules interact with state taxation. They clarified that I wasn't actually being double-taxed but needed to file separate returns in each state where I earned income. The agent also suggested specific forms I should be looking at to claim credits on my state returns. Saved me hours of research and probably a lot of money too. Sometimes being proven wrong is actually the best outcome!

One thing to watch out for with multiple state W-2s is that some states are "convenience of employer" states. NY, NE, CT, DE, PA, and MA can tax you even if you weren't physically working in those states but your employer is based there. That's a situation where double taxation can happen if your resident state doesn't provide a credit for those taxes.

Just want to add that I found out I was being double taxed when I noticed that the "State wages" box on my W-2s added up to more than my "Federal wages" box. If all your state wages add up to more than your federal wages, that could be a red flag for double taxation!

Don't forget part-year resident returns! Since you moved to Idaho, you're a part-year resident there, and you were a part-year resident of the last state you lived in. Part-year returns can be tricky but they're designed to make sure you're only taxed once on each dollar you earn.

I went through a very similar situation a few years ago when I worked in multiple states! One thing that really helped me understand the double taxation issue was checking whether any of the states you worked in have reciprocity agreements with each other. For example, if you lived in Pennsylvania but worked in a neighboring state with a reciprocity agreement, you might only need to file in your home state. However, since you worked in Wisconsin, Nevada, and Pennsylvania, you'll likely need to check each combination. Also, keep all your W-2s handy and look at Box 17 (State income tax) on each one. If you see state taxes withheld, that state will expect you to file a return there. The key is that when you file multiple state returns, each state's tax software should ask about taxes paid to other states - that's where you claim the credit to avoid double taxation. Since Nevada has no state income tax, that's one less return to worry about! But definitely file in Wisconsin and Pennsylvania for the income earned there.