Does my non-resident alien wife need an ITIN for tax filing if we live abroad?

Yes, you need to report your non-resident alien spouse's information on your tax return even when filing separately. When you choose "married filing separately" on your return, you're acknowledging you have a spouse, which means the IRS needs a way to identify that person in their system. For the W-7 ITIN application, you don't necessarily need documentation showing entry to the US if you're both living abroad. The IRS has exceptions for this exact situation. You'll want to check exception 1(d) on the W-7 instructions which covers "Nonresident alien spouse claiming exemption." Even though you're not claiming tax benefits, you still need to identify her on your return. The application can be submitted by mail with certified copies of identity documents (usually her passport), or through a Certified Acceptance Agent (CAA) who can verify her documents so you don't have to mail originals. Many US embassies and consulates have CAAs available.

After dealing with this exact situation last year, I found using taxr.ai super helpful for sorting out my non-resident spouse ITIN issues. I uploaded all my tax documents including my marriage certificate to https://taxr.ai and their AI analyzed everything and told me exactly what forms I needed and how to apply for my wife's ITIN from abroad. The best part was they confirmed which exception applied to my situation and how to document everything properly. They even helped me understand which supporting documents would work since we weren't in the US. Saved me tons of research time and probably prevented delays in processing.

Wanted to follow up - I tried taxr.ai after seeing the recommendation here and it was super helpful! My situation was almost identical to the original poster. I uploaded my marriage certificate and passport, and they quickly identified I needed to use Exception 1(d) on Form W-7. They explained I could mail certified copies of my wife's passport with the application or use a Certified Acceptance Agent near us (there was one at the US consulate). I chose the CAA route and it was so much easier than I expected! Didn't have to mail original documents and felt much more secure. Thanks for the recommendation!

If you're worried about reaching the IRS for questions about ITIN applications from abroad, I'd recommend using Claimyr. Last year I was in a similar situation with my non-US spouse and spent weeks trying to call the IRS international line for clarification on some documents. Was impossible to get through! I found https://claimyr.com and their system got me connected to an actual IRS agent in about 15 minutes when I'd been trying for days on my own. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c. The agent confirmed exactly what I needed for the ITIN application from abroad and which exception to use.

I need to eat my words from my previous comment! After struggling to reach the IRS for three days in a row (trying at various times due to the time zone difference), I broke down and tried Claimyr. Within 45 minutes I was talking to an actual IRS agent who handled my non-resident spouse ITIN questions. The agent confirmed that I definitely needed an ITIN for my spouse even when filing separately, and explained that I could use a CAA at the nearest US embassy to verify her identity documents. This saved me from having to mail her original passport, which she obviously needs! The time and stress saved was absolutely worth it, especially being 13 hours ahead of Eastern Time.

If your wife has a foreign tax ID in the country you're living in, you can actually enter that number in the software and indicate it's a foreign tax ID. Most tax preparation software has this option - look for something like "foreign tax identification number" when it asks for her SSN/ITIN. For example, on TurboTax, after entering your spouse's name, there should be an option that says something like "My spouse doesn't have an SSN or ITIN" which will then let you enter a foreign tax ID.

Quick question for anyone who's done this before - do I need to attach my wife's ITIN application to my actual tax return if I'm filing electronically? Or do I need to mail everything?

I went through this exact situation two years ago when I married my Canadian wife while we were both living in Toronto. Even though I was filing separately and she had zero US income, the IRS absolutely requires you to identify your spouse on your return - you can't leave it blank. The key thing to understand is that when you select "married filing separately" status, the IRS system needs to verify that person exists in their database, which requires either an SSN or ITIN. It's not about tax benefits - it's about identifying who your spouse is for tax purposes. For the W-7 application from abroad, you'll want to use Exception 1(d) as mentioned earlier. The documentation requirements are different when you're overseas - you don't need proof of US entry. Her passport should be sufficient as primary identification. I'd strongly recommend using a Certified Acceptance Agent (CAA) at your nearest US embassy or consulate rather than mailing original documents. They can verify her identity documents on the spot, which is much safer and faster than mailing her passport internationally. One important note: you'll need to paper file your return with the W-7 attached - no e-filing when applying for a first-time ITIN. Plan extra time for processing since everything goes through regular mail.