I'm about to file my 2020 tax, and I realized that I made a mistake in 2018 and 2019 tax return regarding my backdoor Roth. Basically for both years, I didn't report the non-deductible traditional IRA contribution, therefore got the basis wrong and paid tax twice.
Now I have a few questions on how to best move forward.
1. I know my 2019 basis number is wrong on my 2019 tax return, but do I have to fill in the wrong number (as shown on my current 2019 return) in my 2020 return, then amend my 2019 return, and then amend my 2020 return? Or should I put in the correct value on my 2020 return, while filing my 2019 amendment at the same time?
2. I need to file amendment to 2018 return (I contributed to traditional IRA before 4/15/2019 for 2018 quota, but didn't report it on the tax return, because I didn't know I needed to); then I need to amend my 2019 return based on the amended 2018 return. Do I need to wait for the outcome of 2018 amendment before filing 2019 amendment, or I can file two amendments at the same time? 2018 amendment needs to be done on paper, while 2019 one can be done through Turbotax digitally, not sure if it matters though.
Thank you for your help!
