Did you owe taxes last year?
Did your kid graduate college?
Did you get married? or have a baby?
Did you get a raise?
These are all reasons to double check your withholding at work. If you don’t withhold at least 90% of your liability for the year (80% for 2018 due to the new tax laws), there can be penalties. The IRS calls it an “estimated tax penalty” which is really monthly interest. Changing your W-4 at work or paying quarterly estimates can prevent this penalty.
Many people are not aware they are paying a penalty because it is simply included in the total balance due. If you want to check to see if you have paid this penalty, look at Line 23 on your 2018 tax return or line 79 on prior year returns.
The IRS has a calculator on their website to help: https://www.irs.gov/payments/tax-withholding
Or you can ask your tax professional for a meter reading to make sure you are on track for the year.