Quarterly estimates
What to pay each quarter, calculated from actual year-to-date profit.
An estimate built in January from last year is a guess that gets worse every month. This one recalculates from the books as the year runs.
Both the safe harbour amount and the current-year calculation are shown, because the smaller of the two is usually what you should pay.
Where everything sits
How to work this page
Safe harbour is based on last year and protects you from penalty. Current year is what you actually owe. Paying the lower of the two is normally correct.
A strong quarter raises the estimate. Seeing that in month two rather than at the deadline is the point.
The reserve builds through the quarter so the payment is already covered.
Underpayment penalties accrue from the quarter missed, not from the year end.
On a phone
Every figure from the desktop appears here, stacked rather than reduced. Tables scroll inside themselves so the page never moves sideways, and figures keep their separators and their alignment at every width.
Questions people actually ask
Paying a set percentage of last year's tax generally protects you from underpayment penalty regardless of what this year does. The percentage depends on income level and is stated on the page.
The estimate falls and may reach zero. Overpayments from earlier quarters carry forward rather than being lost.