Thanks for bringing this to our attention, @c winter.
When your e-file is rejected in QuickBooks Desktop (QBDT) due to duplicate tax filing, it means that the IRS or state agency received two tax forms with your information for the same period. It usually happens if you've used more than one payroll provider in the same quarter and forgot to cancel one.
Since you've experienced e-file rejection, you'll need to contact the IRS or the state agency to confirm whether they accepted one form or rejected both. Depending on the situation, you may also need to file an amendment or resent the form through the agency.
I'll share this article for more information: Handle payroll e-file and e-pay rejections.
Additionally, you're free to access your filed tax forms and paid tax payments anytime in QBDT to keep track of your tax compliance and ensure that you have paid all your taxes correctly and on time.
Please don't hesitate to swing by the Community whenever you need further help e-filing your W-2s in QBDT. I'm always available to help. Stay safe.