If Box 2, "Federal income tax withheld," is blank on the W-2 form you file with your annual tax return, your employer either didn't withhold taxes or an error occurred in transferring the information to the form. If you didn't have money withheld, you must pay your federal tax when you file a return. If you believe an error occurred, check with the employer.
Federal Tax Obligations
In a traditional employment relationship, your employer typically withholds federal and state taxes, along with other taxes and deductions. The amount withheld is based on the number of allowances and other information you provide on federal W-4 form. You should see any withholdings indicated on each pay stub. If you didn't complete a W-4 form or your employer didn't withhold taxes, you pay your federal taxes when you file. To avoid this problem in the future, you should complete a new W-4 form right away to have the proper amount withheld for the next tax year.
A simple explanation for Box 2 being blank is that your employer did withhold federal taxes and made a mistake when reporting the data on your W-2 form. Errors may result from printer problems or glitches in the organization's software program. Contact your employer and get a corrected copy of the W-2 form.