I (regrettably) converted my 401k which contained Pre-Tax and After-Tax money into a Roth 401k, meaning I need to pay taxes on the Pre-Tax and After-Tax gains as it they were income. This was done in Jan 2024.
My understanding is after I file taxes for 2023, I need to look at my 2023 Form 1040 and view line 24 (total taxes). Then I need to view my paystub to see how much will be federally held by my employer. If the amount withheld by my employer is equal or greater than line 24 of my 2023 Form 1040, I don't need to do anything until April 2025 where I will have to pay the taxes on my additional income from my 401k conversion.
If the amount withheld is less than line 24 of my 2023 Form 1040, I will need to add withholdings to my W4 line 4c to withhold from each paycheck the difference in value between my 2023 Form 1040 line 24 and my employer's federal withholding.
Is this correct?