By default, Form 2210 requires evenly spread Estimated tax + withholding installments.
you must estimate your total tax for the year,
you can base your estimate on prior year's tax , or 90% of this year's tax, whichever is smaller.
each quarter your estimated tax paid and withheld must be at least 25% of the estimate, even if your income is uneven,
if your estimate is based on 90% of this year's tax and turns out to be wrong you may be penalized.
you can compensate by overestimating.
if your estimate is based on prior year's tax, you know that when you file by April 15, which is also the first estimated tax payment due date. How convenient.
If your quarterly withholding and estimates in 2023 are at least 100% / 4 = 25% ( 110% / 4 for certain high income taxpayers) of your 2022 tax, there will be no penalty on your 2023 tax return, regardless of any jump in income.
you are protected from a sudden capital gain or bonus at year end.
@Rcastel
