What states typically require you to file nonresident tax returns? Criteria explained

Thanks for the detailed response. Two questions: 1) If I traveled to California for a company meeting for like 3 days this year, does that change things? and 2) Does it matter that my W-2 lists the California address of my employer even though I work remotely?

Yes, traveling to California for work, even just for 3 days, can potentially trigger nonresident filing requirements. California has no minimum threshold of days - technically any work performed physically in the state creates California-source income that may need to be reported. The fact that your W-2 shows a California address for your employer doesn't automatically create California income. What matters is where you physically performed the work. However, this might flag your return for review by California tax authorities, so it's important to properly document your work location. You'll likely need to file both a Colorado resident return (reporting all income) and possibly a California nonresident return (reporting only income earned while physically in California).

Does it actually tell you the specific thresholds for each state? I travel for work to like 5 different states and I'm never sure which ones I need to file in.

How accurate is this? I've been burned before by tax software that missed state-specific rules. Do they keep up with all the weird state rules like NY's convenience of employer stuff?

Yes, it gives you the specific nonresident filing thresholds for each state - both dollar amounts and day counts where applicable. It really helped me understand which of my short business trips actually created filing requirements. The tool definitely covers the convenience of employer rules. That was actually my main issue since I work remotely for a New York company. It explained exactly how those rules applied to my situation and what documentation I needed to maintain. I found it way more specific to multi-state tax situations than general tax software.

How does this actually work? Does it just call the tax department for you? I'm confused why I would need a service for that.

Sounds like a scam to me. Why would I pay someone else to call the tax department when I can just do it myself for free? Tax departments have to answer their phones eventually.

It doesn't just call for you - it navigates the entire phone tree and waits on hold so you don't have to. When a real person finally answers, it calls your phone and connects you directly to the agent. You don't waste hours listening to hold music. Have you tried calling state tax departments lately? I spent 3+ hours on hold with California multiple times and got disconnected each time. Some state tax departments are literally unreachable right now with hold times exceeding 4-5 hours, and they often disconnect calls after 2 hours. This service basically waits in the phone queue for you. If you've had success getting through on your own, you're extremely lucky!

What happened with your Massachusetts situation? Did you end up having to pay taxes there even though you never went there?

I ended up not having to pay Massachusetts taxes, but it required some work. I had to provide documentation showing that I was required to work remotely (not doing it for my convenience) because my position was permanently remote. I also got lucky because during the pandemic, Massachusetts temporarily suspended some of their convenience rules, and my situation fell within that timeframe. Had it been a different year, I might have had a bigger fight on my hands. The key was proving that working remotely was a requirement of the position, not just my personal preference.

This is super helpful! Do you know where to find an official list of all these reciprocity agreements? Is there some IRS page that lists them all?

The IRS doesn't actually maintain a list of reciprocity agreements since these are state-level agreements, not federal. Each state's department of revenue website usually has information about their specific reciprocity agreements. You can also check the Federation of Tax Administrators website (taxadmin.org) which has some good resources on interstate tax issues. But honestly, the most reliable way is to check both states' tax department websites directly since these agreements can change and you want the most current information. For anyone dealing with multi-state issues, it's also worth noting that reciprocity agreements typically only apply to wage income - if you have other types of income like rental property or business income in a state, you might still need to file there even with reciprocity.

This is exactly the kind of detailed breakdown I was looking for! The threshold amounts really help put things in perspective. So for my California situation with just 3 days of work there, I'd need to calculate what portion of my annual income was actually earned during those specific days in California, and if it's a small amount, I might not even need to file there at all. Do you happen to know if there are any good resources for calculating the daily income allocation? Like if I make $80k annually, how do I properly determine what 3 days of work in California would be worth for tax purposes? Also, thanks for mentioning the credit for taxes paid to other states - I hadn't thought about that aspect yet but it's definitely something I'll need to factor in when deciding whether to file multiple returns or not.

For calculating daily income allocation, the most common method is to divide your annual salary by the number of working days in the year (typically around 260 days, assuming 5 days/week for 52 weeks minus holidays and vacation). So with your $80k example, that would be roughly $307 per day. However, some states have specific rules about how to allocate income. California, for instance, generally looks at where you physically performed the work, so those 3 days would likely be calculated as 3/260 of your annual income, which would be about $923 - well under most state thresholds. The tricky part is that you need to be very precise about this allocation and keep good documentation. I'd recommend keeping a detailed work log showing dates, locations, and nature of work performed. Some people even take photos or keep hotel receipts as backup documentation. One thing to watch out for - if your employer withheld California state taxes from your pay (even for remote work), that might complicate things and could require filing even if you're under the threshold, just to get a refund of the withholding.

This is such valuable advice, especially the point about keeping detailed work location logs! I wish I had started doing this earlier in the year. Quick question - when you say "type of work performed," do you mean just general categories like "client calls" or "development work," or do you track more specific details? Also, your point about employers getting withholding wrong is really important. I just checked my paystubs and noticed my employer has been withholding Colorado taxes (where I live) but not California taxes (where they're based), even though I work remotely. Based on what others have said in this thread, that actually sounds correct for my situation, but it's good to know I shouldn't just assume the withholding tells the whole story. The audit timeline you mentioned is a bit scary - 2-3 years later! Do you know if there's a statute of limitations on how far back states can go for these remote worker situations?

For the work location log, I keep it pretty simple - just general categories like "client meetings," "development work," or "administrative tasks" are fine. The key is showing WHERE you performed the work, not necessarily every detail of what you did. Regarding the statute of limitations, most states follow a 3-4 year rule for tax audits, but it can extend to 6 years if they suspect substantial underreporting of income (25% or more). A few states like California can go back even further in certain circumstances. The clock typically starts from when you filed the return or when it was due, whichever is later. Your withholding situation sounds correct based on what you've described - Colorado resident working remotely should generally have Colorado taxes withheld. Just make sure you're documenting that remote work arrangement well in case California ever questions it. The pandemic really changed the remote work landscape, and tax authorities are still catching up with enforcement, which is why we're seeing these delayed audit notices. One more tip: if you do get any kind of tax notice from a state you think you don't owe taxes to, don't ignore it! Even if it seems wrong, you usually have a limited time window to respond and provide documentation.