Quarterly estimates without the guesswork

Estimated taxes generate more client anxiety per dollar than any other filing — mostly because people try to predict the future. The safe-harbor rules exist so you do not have to.

The two safe harbors

Pay in, through withholding and estimates, either 90% of the tax you will owe this year, or 100% of last year’s tax — 110% if your adjusted gross income topped $150,000. Hit either target on time and there is no underpayment penalty, whatever the final bill turns out to be.

For anyone whose income is growing, the prior-year harbor is the calm choice: it is a known number, divisible by four, decided in April. Your actual liability gets settled at filing time, with no penalty riding on the estimate.

The calendar that makes it automatic

The due dates are April 15, June 15, September 15 and January 15 — note the uneven gaps. We set every client’s payments up in April, schedule the transfers, and revisit only if the year changes shape: a big asset sale, an acquisition, a windfall quarter.

Underpaying costs interest at rates that have recently hovered around 8%. Overpaying is an interest-free loan to the Treasury. The safe harbor threads the needle — which is why it is the default in every plan we write.