there are other rules that go with the 90% rule
1) withholding is deemed to be 1/4 of the annual total for each tax period. You do have the option of using actual for each period
2) most importantly estimates only count for the period in which mad and subsequent periods,
the default method
say your tax was $2000
withholding was $1000
and you paid an estimate of $1000 on 5/15/2024
90% of your tax for each period would be $450 (2000/4*.9)
withholding for each period would be $250 (1000/4)
since the estimate was not paid until the second period you have a $200 underpayment for the first period
you do have the option of completing the Annual Income Installment method on page 3 of the 2210 to see if that lowers your pnalty
