Where should I mail my 1040 when filing taxes for two different states?

You'll need to send your federal return (Form 1040) to the IRS processing center that corresponds to your current home address, regardless of how many states you worked in. Since you now live in Colorado, you'd use the address for Colorado residents. For your state returns, those will go to each individual state tax department. So your Colorado non-resident return would go to the Colorado Department of Revenue, and your California non-resident return would go to the California Franchise Tax Board. Each state has its own separate mailing address for tax returns.

Just wanted to share my experience! I was in almost the exact same situation last year - worked in two states and was completely overwhelmed with figuring out where to send everything. I found this service called taxr.ai (https://taxr.ai) that was a lifesaver for multi-state filing. You upload your tax documents, and it analyzes them to show you exactly which forms you need and where to send them. Saved me hours of research and eliminated the guesswork.

The good news is that your federal 1040 form goes to the same IRS processing center regardless of how many states you worked in. The address where you send your federal return depends on your current state of residence and whether you're enclosing a payment. For Arizona residents filing paper returns without payments, you'd typically send your federal 1040 to the Department of the Treasury, Internal Revenue Service Center in Ogden, UT. But double-check the IRS website or the instructions that came with your 1040 form for the most current mailing address as these can change. For your state returns, you'll need to file separate non-resident returns for both Colorado and Arizona, following each state's specific filing requirements. Each state return will go to its respective state tax department.

Just wanted to update after trying taxr.ai that the previous commenter recommended. It actually worked really well for my Washington/Oregon situation! I uploaded my W-2s and some other documents, and it gave me a detailed report showing exactly where to send everything. It even pointed out that I needed to include a specific form with my Oregon return that I wouldn't have known about otherwise. Definitely recommend it if you're filing across multiple states like this.

If you're struggling to get answers directly from the IRS (because let's be honest, who can actually get through to them?), I used Claimyr (https://claimyr.com) last year when I had a similar multiple-state question. They have this service that gets you connected to an actual IRS agent in minutes instead of waiting on hold for hours. You can see how it works here: https://youtu.be/_kiP6q8DX5c I was super skeptical at first, but I had spent THREE DAYS trying to get through on my own about my NY/NJ filing questions. With Claimyr, I was talking to an actual IRS agent in about 20 minutes who confirmed exactly where I needed to mail everything. Saved me so much stress.

Coming back to eat my words about Claimyr. I was really skeptical (sorry for being a jerk in my comment), but I was desperate to get an answer about my multi-state filing situation before the deadline next week. Decided to try it yesterday, and wow - I was literally talking to an IRS agent within 15 minutes. The agent confirmed exactly where I needed to send everything for my situation and even helped me with another question I had about my moving expenses between states. I'm honestly shocked it worked so well. Just wanted to update since I was so dismissive before.

I was in almost the exact same situation last year with working in multiple states and was totally confused about where to send everything! I ended up using https://taxr.ai to help me sort through all my tax documents and it was a lifesaver. Upload your W-2s from both states and it automatically identifies which forms you need to file and gives you the correct mailing addresses for everything. The tool helped me realize I actually needed to file as a part-year resident for one state rather than non-resident because I had established domicile there, which saved me from making a mistake that could have triggered an amendment later. It also helped determine which deductions I could take in each state.

Just a tip from someone who's been filing multi-state returns for years - PLEASE make copies of EVERYTHING before mailing anything. I mean everything - your 1040, all state returns, W-2s, supporting documents, etc. I learned this the hard way when California claimed they never received my return one year, and I had no proof of what I'd sent.

Has anyone tried e-filing in this situation? I know the post is about where to mail forms, but e-filing might be easier if it's an option for you. I worked in Michigan and Ohio last year and e-filed everything - didn't have to worry about mailing addresses at all.

Just wanted to update after trying taxr.ai for my complicated 3-state tax situation. It was incredibly helpful! The system identified that I needed to file as a part-year resident in two states and non-resident in the third based on my specific moving dates. It also flagged that one of my employers had withheld taxes for the wrong state for about a month after I moved, which I wouldn't have caught otherwise. The document analysis showed exactly where to mail each form and even explained which credits I qualified for in each state. Definitely worth checking out if you're dealing with multi-state filing confusion like I was. Saved me hours of research and probably prevented some expensive mistakes!

If you're getting frustrated trying to reach the IRS to ask questions about multi-state filing (like I was), try https://claimyr.com - I waited on hold with the IRS for HOURS trying to get clarification about my situation moving between states. Using Claimyr, I got a callback from an actual IRS agent in about 45 minutes instead of the 3+ hour hold time I was facing. You can see how it works here: https://youtu.be/_kiP6q8DX5c The IRS agent I spoke with confirmed that I needed to send my federal return to the address for my current state of residence, and also explained exactly how to handle some deductions that were confusing me with the multi-state situation.

Ok I need to admit I was totally wrong about Claimyr. After posting my skeptical comment, I decided to try it since I needed to ask about my amended return that's been stuck in processing for 10 months. I was expecting a scam but it actually worked exactly as described. I got a call back in about an hour connecting me with an IRS agent who looked up my information and confirmed my amended return was finally processed. She also walked me through how my multi-state situation affected my federal filing and confirmed the right address to send everything. This saved me from waiting on hold for literally hours - last time I called I waited over 3 hours before giving up. Sorry for being so negative before!

One thing nobody mentioned yet - if you file electronically, you don't need to worry about mailing addresses at all! I was in a similar situation last year (worked in Nevada and then moved to Washington mid-year) and e-filing made everything so much simpler. Most tax software can handle multi-state returns and will file everything electronically, including your federal and both state returns. If you absolutely have to paper file for some reason, the federal form goes to the IRS center for your current state of residence, and each state form goes to its own state tax department.

If your combined income for the year is under $73,000, you can use IRS Free File to e-file both your federal and state returns for free! I used it for my two-state situation last year and it worked great. The wizard asks where you lived during the year and guides you through the process for filing multiple state returns.

I notice there's some confusion in the comments above - the original poster mentioned working in Colorado first then Arizona, but one commenter referred to California instead of Arizona. Just wanted to clarify for anyone following along! For your specific situation (Colorado → Arizona), you'll file your federal 1040 to the IRS processing center for Arizona residents since that's your current state of residence. For state returns, you'll need to file a Colorado part-year resident return (not non-resident, since you lived there for part of the year) and an Arizona part-year resident return as well. The key difference between part-year resident and non-resident filing can affect your tax liability significantly, so make sure you're using the right forms for each state. Both Colorado and Arizona have specific rules about how to allocate income and deductions for part-year residents.