Are you sure, look at the year located on your W-2 and make sure that it matches the year associated with the software you are using. Then contact customer support to delete the return.
You cannot change or add anything on the return that you e-filed. It is too late, just like when you put an envelope in a US mailbox
Now you have to wait until the IRS either rejects or accepts your return. If your return is rejected, you will be able to go into your account and make the necessary changes to your tax return and re-submit your return with the right year info.
If the IRS accepts your return, then you have to wait until it has been fully processed and you have received your refund. THEN you can prepare an amended tax return 1040X and mail it in. You cannot e-file an amended return. Meanwhile, DO NOT change anything on your return until you start the amended return.
How to amend 2018,
https://ttlc.intuit.com/questions/4667226-how-do-i-amend-my-2018-turbotax-online-return
Then do you still need to file a 2017 return or amend one you did file?
Yes I filed 2018 under 2019 ani I go a bill from Irs
The year on the forms must all match and go on software with the same year to follow the laws for that year.
If you have already filed a return on the wrong year and it has been accepted and the financials are settled, you need to file an amended return and use the correct forms for that year. You can NOT amend if the finances are not settled.
You need to file an original return for the year that you did not file. If you have a bill from the IRS, do the return immediately. You should also call the IRS to see where to mail your return or if they will take the fax. Each agent and department is a little different. The address to mail can vary depending on the substitute return they filed for you. You can NOT use the address in the normal directions.
Links you need:
Here is a link for how to prepare prior year returns.
How to file an amended return on the software.