This is what I plan to do in December. I'm looking for advice as to how to handle the income tax payment.
Up until this tax year, I have made quarterly estimated tax payments. This year, with the option to not take my RMD pull (I am 76), I elected not to make quarterly tax payment since my trial tax return says I will owe NO TAX on my income this year (2020) without pulling the RMD.
This zero tax owed is due to having only income from SS (about $45K) and interest from MM & CDs ($10K). This income for seniors filing married jointly amounts to $0 tax owed when doing a trial return.
What I plan to do is convert, say $30k, to a Roth in December and that amount will have me owing income tax on about $20K of it. (I may convert more).
If I do the conversion in December, when will I have to pay the tax? And since I declined to pay estimated tax quarterly (even though I didn't owe any at that time), am I facing any penalty?
I think you'll be fine paying the tax on Jan 15, 2021, with no penalty. Although I'm not sure what happens with ZERO withholding in 1Q-3Q. Might be a small penalty because you DID have income in those quarters.
If you want to be sure, just run your 2020 trial tax return through 2019 TurboTax. At first, it will likely say you owe a penalty due to underwithholding. But go through the Form 2210 process and see what it says. My guess is that you'll either owe no penalty or some very nominal amount. Just keep in mind it's all based on 2019 brackets, deductions, etc... the answer could change a bit when you run it for real through 2020 TurboTax.