If the control number on my w-2 isn't working, what should i do? And can't find it on last years w-2?

[Ashby · Accepted solution]

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). The IRS doesn't care what's in Box D because its use by payroll departments is optional.