Do estimated taxes need to be paid in the quarter that a gain on real estate is realized?

[IsabellaG · Accepted solution]

Yes they can be. Since it is a pay-as-you go system, if you have a significant income in a particular quarter, and you anticipate that you would owe additional tax on that income, the estimated tax payment would be due in that quarter. 

But keep in mind that you are subject to an estimated tax penalty if you have a balance due of $1000 or more, but you can avoid the penalty if you have paid in at least 90% of the current year's income taxes or 100% of the previous year's taxes. 

See this link, particularly under When are my estimated taxes due?