When I am ready to e-file I get a problem fixing the Utah return. It asks me to go back to federal W2 to update the employer state withholding ID. But I cannot

 If you have not mailed it yet, yes!!  E-filing does not start until the 12th, so as long as you have not put it in the mail yet, you can still e-file.     If you already put it in the mailbox, it is too late to e-file.     But, if you did not mail it yet, you can still update the information and e-file.  

If you printed your taxes to mail them in and went all the way through the File section, when you sign in to TurboTax Online you'll see the Way to go! You filed your 2020 taxes and you won't see a way to change to e-filing. As long as you haven't already mailed your 2020 paper return, you can switch to the e-filing method (through October 15, 2021). However, some states now require e-filing, which means the federal and state must be e-filed together.

If you already mailed your return, don't e-file. This can cause problems with the government, including refund delays.

1. In TurboTax Online, sign in to your account.
2. Select Tax Home in the left menu.
3. Scroll down to Your tax returns & documents.
4. Select 2020, and then select Add a State (you're not actually adding a state, this just gets you into the right area).   
5. Update the W-2 information.
6. Select File in the left menu (expand your browser window if you don't see this, or select the menu icon in the top left corner).
7. On the Just one more step screen, follow steps 1 and 2 if you haven't already.
8. Select the Start button to the right of Step 3.
9. On the Let's get ready to e-file screen, select I want to e-file.
10. Follow the instructions to e-file your return.