I need to file tax returns for 2019, 2020 and 2021. No taxes are due, and I should be getting a refund for each year. I also need to apply for an ITIN for my wife. What would be the correct or optimal way to go about it? I can see the following choices:
1. File W7 for my wife and attach all three returns together. Is this allowed and/or recommended?
2. File W7 along with 2019 return.
3. File W7 along with 2021 return.
Also, will any of these choices above affect the speed of issuing of the ITIN ?
