I do not have a K-1 form. I also did not have any investment sales/rental/royalty income, etc. The reasons listed by Turbo Tax why I would need the Premier edition did not apply to me at all. In fact, I had no changes in anything from last year and I was able to use the Deluxe for 2017. I see the response that I could Clear & Start Over, but really? I was 100% done with everything and was ready to file when it showed that I owed for Turbo Tax Premier. Very disappointed.
You must have entered some tax data or indicated that you needed to enter tax data that was not supported on the Deluxe edition. The Premier edition supports entry of investment sales and rental/royalty income/expenses that is not supported on the Deluxe edition.
If you have not paid for the online edition you are using, have not filed your tax return or registered the Free edition, then you can clear your return and start over with a lower priced edition. Click on Tax Tools on the left side of the program screen while working on the 2018 online tax return. Click on Clear & Start Over.