What Is a W-2 Control Number?

Have you ever wondered what all of those numbers on your W-2 form, or wage statement, mean? Some are fairly obvious, such as your Social Security number and your employer's tax identification number. These numbers are both unique to you and your employer. There's another unique number on the form, and that is the W-2 control number. The W-2 control number appears in Box d of your form, between your employer's name, address and ZIP code and your name, address and ZIP code. It is actually a code identifying the "unique" W-2 form in the records of your employer, assigned by the company's payroll processing software. It is merely an aid in processing and tracking, especially when the company has a great many W-2 forms to send out.

What Is a W-2 Control Number?
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A Blank Box D

Although you must report any errors on your W-2 to your employer, a blank box D is not cause for alarm or for employer notification. Not every W-2 will include a number in box D. If you work for a small company with only a few employees, the control number is not necessary for tracking purposes. The number, or lack of it, does not affect the completion or processing of your income tax return, although you may experience a technical difficulty when e-filing. The use of a W-2 control number is optional for employers and is not mandated by the IRS. The IRS does not require it for any portion of your income tax return. If your employer doesn't use control numbers for payroll processing, the box is simply left blank.

E-Filing With No W-2 Control Number

You might run into problems with no control number on your W-2 when e-filing your tax return. It is possible you will receive an error message when trying to e-file with an empty box d. Since the number has no significance to the IRS, you can enter a number at random in the proper format to have your file accepted. The formula is simple: Five digits, a space, and five more digits. You could use 11223 34455. However, trying to import your W-2 without a control number requires a different solution. In this case, click the "skip import" tab and enter your W-2 manually. Importation does not allow you to use the numeric code for the control number.

Different Year, Different Control Number

Your W-2 control number will not necessarily remain the same year after year, even if you are working for the same employer. The decision is totally up to the employer's discretion, but it may change annually for security purposes.