What are you seeing and where are you seeing it? When did you file a 2018 tax return--and using what software? It has been impossible to e-file a 2018 return since mid-October of 2019. If you more recently used the online software to prepare and file a 2018 return, you made a big mistake, since online is ONLY for a 2019 return. If you used online you used the wrong software.
When you e-file a return, you get several e-mails. The first one just says that your e-file has been submitted. The next one tells you if the return was accepted or rejected. So....are you confused about that? Did you think you e-filed a 2018 return--and now you are seeing that it was rejected?
If that is the situation---be relieved that it rejected, so that you can prepare and file your 2018 return correctly using the right software.
Please post back by clicking "Reply" and tell us what you did so we can make sure you are fixing this.
Online preparation and e-filing for 2016, 2017 and 2018 is permanently closed.
To file a return for a prior tax year
If you need to prepare a return for 2016, 2017, or 2018 you can purchase and download desktop software to do it, then print, sign, and mail the return(s)
https://turbotax.intuit.com/personal-taxes/past-years-products/
You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.
Remember to prepare your state return as well—if you live in a state that has a state income tax.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
Note: The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac. It cannot be used on a mobile device.
If you are getting a refund, there is not a penalty for filing past the deadline. If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.