This year, Paula and Simon (married filing jointly) estimate that their tax liability will be $200,000. Last

Question:

This year, Paula and Simon (married filing jointly) estimate that their tax liability will be $200,000. Last year, their total tax liability was $170,000. They estimate that their tax withholding from their employers will be $175,000. Are Paula and Simon required to increase their withholdings or make estimated tax payments this year to avoid the underpayment penalty? If so, how much?