If you are having problems submitting them after entering line D (your control number) please see below:
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 or you enter what is there and it's not taking it, it's no big deal – you can simply leave it blank OR
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 or play around with the numbers but try to stick to the format suggested with the space in the middle.
Please let us know if you have anymore questions, we are happy to help you.