When I click on efile it says my control number for one of my W-2s is invalid although it’s entered correctly. Is there a way to fix this?

[LeeM · Accepted solution]

You can leave it blank or follow the step below if you want to enter a number that will work. The IRS doesn't care what's in Box D because its use by payroll departments is optional.

A Control Number (Box D) is used by many payroll departments to uniquely identify a W-2 in their system. If your W-2 doesn't have one, it's no big deal – you can simply leave it blank.

If you get errors when attempting to e-file with an empty Box D, just enter any number in this format: 5 digits, space, 5 digits (for example, 12345 67890). 

On the other hand, if you're trying to import your W-2 with a blank Box D, click skip import and then manually enter your W-2. You won't be able to import using the 5 digit + space + 5 digit solution for e-filing.