So you owe the IRS a lot of money? Here’s what to do.

Warm temps and patio happy hours are on the horizon, so you know what that means: It’s time to play the IRS’s favorite twisted (and forced) guessing game: We’re going to make you figure out how much you owe us in taxes, even though we already know! 

If you aren’t super financially savvy — which, if you graduated from the US school system, where learning to square dance took precedence over financial literacy, might be the case — that lack of knowing might feel anxiety-inducing. And if...