Please help me understand the whole process.
To me, the process starts with the IRS safe harbor provision. Safe harbor is what you have to do to prevent receiving a penalty for underpayment of taxes. You can:
a. pay in 90% of your current year (2023) tax liability.
b. pay in 100% of last years tax liability or 110% if your agi is over $150K.
Here's what I did.
Throughout the year, I have an amount withheld from my pension. Let's say that totals $3K Fed and $1K State. Assume my 2022 tax liability was $8K for Fed and $3.5K for State. Therefore, I needed $8.5K more to be withheld - $5K Fed and $2.5K State. Now I'm good for safe harbor. If my taxes are more in 2023, I'll just pay it with my return in April. No penalty and I didn't have to estimate my taxes or pay estimated taxes throughout the year.
I took that money from my IRA and had my representative send $5K to the Fed and $2.5K to the State. The withdrawal was 100% withholding.
Then, I did estimate my year end income to see where I was versus the 12% tax bracket. My goal is to hit that level of income. If I'm low, I'll do a ROTH conversion. If I'm over, I messed up. Not much I can do about that.
Except, I realize, thanks to this thread, that I can at least put the $8.5K back in my IRA (thankfully, I was still within the 60 days) and save paying the 22% on that amount. So I called my rep today and had them pull $8.5K out of my checking and consider it a rollover into my IRA.
A little different than your example, but that's what happened.
In simple terms, the strategy is this:
Pay in enough to cover safe harbor. One could pay no taxes throughout the year and then do a withdrawal from your IRA at 100% withholding before year end to cover safe harbor. Then, turn around and pay that money back to your IRA (from a taxable account) and not have to pay tax on that withdrawal. You'd want to do this in the same year to simplify tax return preparation.
Hope that answers your question.