@ nehamalhotra23 wrote: "I didn't file 2018 taxes. I did buy a TT subscription for filing the taxes, though. What process, if at all, can I follow on this website to file 2018 taxes?"
You used the term "subscription." Please describe what you bought--TurboTax desktop software subscription, or did you pay for 2018 Online TurboTax? It's not clear how you are using that term.
For example, are you a TurboTax Advantage member with an annual subscription for the desktop software? If so, there should be a 2018 program download in your account that you can use to prepare the 2018 return. We can tell you how to look once it's clear what you mean.
Or did you pay for Online TurboTax 2018 but never filed? If so, we can tell you how to ask TurboTax Support for the 2018 download software. You should not have to pay again.
The 2018 return cannot be prepared online, and it cannot be efiled. It will need to be printed, signed, dated, and mailed. It's a good idea to mail by a method that has tracking, such as certified mail, priority mail, etc.
If you have both Federal and state returns, you need to mail each one separately to its respective tax agency.
NOTE: If it turns out that you started and paid for a 2018 return in last year's 2018 Online TurboTax, we can tell you how to download the *.tax2018 data file, if you wish, to continue it in the 2018 desktop software without starting over.
