When online opens in December you can transfer from the 2018 file that's on your computer.
If you used the Desktop program last year here’s How to transfer into the Online version, expand the link if you used the CD/download last year........
If you used the Desktop program before you may not like the online version. It has less features and no Forms Mode. You can only do 1 return. Your return is only saved online so be sure to save both the .tax2019 data file and the pdf file to your computer when you are done. In case you need to amend in the future or if you need a copy to get a loan or something. You might not be able to access your online return when you need a copy.
If you mean how to transfer the 2018 tax info from the 2018 downloaded version to the 2019 version ... just follow the screen instructions :
2018 Downloaded to 2019 Online
Last year's tax data file (.tax files) can be transferred to the Online versions.
- Sign in to TurboTax Online, if you haven't already done so.
- Select Tools on the menu bar lower left on the screen.
- In the pop-up window, select Transfer last year's TurboTax return from your computer.
- Read the warning and then click Continue (or Cancel to abort the transfer).
- Browseto where you saved your .tax2018 file and select it.
- ClickTransfer Return and wait for your file to finish uploading.
- When you see Transfer Complete, click Continue to start working on your return.