re: #85 calochortus

Except I believe that if you pay as least as much as you did last year, even if it isn’t 90% of your tax due, you’re OK. However, I am in no way a tax professional, so you might want to check that before putting it into practice.

It’s …complicated, and depends on your income bracket to boot. The short summary:

Your total tax payments made before before January 15th must add up to the lessor of these two amounts:

90 percent of the tax you owe for the current year, or
100 percent of the tax you owed for last year. If your 2012 adjusted gross income was more than $150,000 (more than $75,000 if married filing separately,) substitute 110 percent for 100 percent.

In general meeting the number means that we end up with some sort of refund, depending on how much over we were. It is still preferable to a significant penalty.

(ETA: Summary from here. I don’t feel like stabbing my eyes out to find the IRS version.)