You may have submitted an incorrect W-4, or someone at your employer may have entered it into the computer incorrectly. You have to talk to your employer and maybe submit a new W-4.
It’s important to understand that the W-4 has four pages, not just the front page that you submit to your employer. The other three pages are instructions and worksheets for situations where you have more than one job or where you are married and your spouse also works. In the situation you have to follow the instructions and complete the worksheets or use an online tool to determine how to adjust your withholding correctly. If you have more than one job or if you are married and your spouse works and you do not make these adjustments, you will not have enough tax withheld. When you do these worksheets or use the online tool, it will give you a recommendation and you will update your W-4s at all of you and your spouses jobs, not just the job you are thinking about. Your W-4s have to be coordinated and updated at the same time.
