If you have not already filed you may be able to "Clear and Start Over." In the left-hand column choose "TAX TOOLS" then "TOOLS"===>"Clear and Start Over"
If you have filed the return and the return contains incorrect or incomplete information taxpayers file an amended return (1040X). Allow time for the original return to be fully processed by the IRS prior to filing the amended return. TTX will guide you through the Amended return process. NOTE: Amended Returns are "Old School" Print/Date/Sign/Mail---no efiles available.
Have you already filed? If you missed adding a W2 or should have corrected one when filing your tax return, you'll want to determine if the IRS or state has accepted your tax return. You can check your refund status here. If they have accepted your return, then you may need to amend your tax return. If your return was rejected, you can correct the W2, and correct the reason for rejection and resubmit. You will receive an email from us on how to fix the return.
Please see these TurboTax FAQ's for more information:
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/00/27577.
If you haven't filed you can delete the W2 and then correct it when you need to:
Please follow the steps below to delete a W2 in TurboTax: