The control number is an optional field that employers can use to internally identify and track individual W-2 forms. It is not required by the IRS and does not need to be included on the W-2. The control number allows an employer to organize and reference the W-2s they issue to employees.
It is a unique number that the employer assigns to each Form W-2. While this number may help an employer keep track of W-2s, it is not used by the IRS or necessary for tax filing purposes.
What is the control number field in form W-2?
The control number is an optional field that employers can use to internally identify and track individual W-2 forms. It is not required by the IRS and does not need to be included on the W-2. The control number allows an employer to organize and reference the W-2s they issue to employees.
It is a unique number that the employer assigns to each Form W-2. While this number may help an employer keep track of W-2s, it is not used by the IRS or necessary for tax filing purposes.
Last modified: December 23, 2025
