That's actually okay, and you can still easily file your tax return without one. Not all W-2s have Control Numbers associated with them, or printed on them. Please allow us to explain.
Form W-2 (wage statement) Box D is a Control Number field. It is usually located below the Employer's Name and Address.
The Box D Control Number is a code that identifies your unique Form W-2 document in your employer's records. This number is assigned by the company's payroll processing software, and is needed if attempting to electronically import your W-2 into a tax software program (like TurboTax). Please note that not all W-2s (or employers) will necessarily include a Box D number. Your alternative to importing a W-2 document is to simply input the same information manually.
The actual Control Number itself is basically irrelevant to completing your tax return, unless you wish to import your W-2 into TurboTax; and it that one instance it is required. In other words, the W-2 Control Number, whatever it is, will never increase or decrease your actual tax refund (or your amount owed) by a single penny.
If you type in your W-2 manually, rather than importing it electronically, then you should not have to enter anything from Box D at all. In fact, you should be able to simply leave the field blank. The exceptions to that would be if you are attempting to e-file your return and see some sort of W-2 Control Number related error; or if the program insists on a value before allowing you to continue. In those cases, we have a TurboTax FAQ article that can help. I've linked this answer to that FAQ page below.
I hope this information is useful to your needs. Thanks for asking this question.
https://ttlc.intuit.com/replies/4417180
My we does not have a control number so how would I file
W2 box d Control number is not needed. See
https://ttlc.intuit.com/community/forms/help/i-have-no-box-d-or-control-number-on-my-w-2/00/26469