@fanfare wrote:
Once IRS applies a penalty you can dispute in writing, but without an alternative calculation, like Form 2210-AI , expect to not succeed.
@maryrupp
Taxpayers who have never paid a penalty before can apply for a one-time waiver, there are also waivers for cause. (This is different from requesting a recalculation.). Note that interest can't be waived.
https://www.irs.gov/payments/penalty-relief-due-to-first-time-abate-or-other-administrative-waiver
