The 2018 tax software uses the .tax2017 datafile, right at the very start of a new 2018 tax file......provided that is is on your computer disk.
So, before you start a new 2018 tax return (really the first one for 2018 for you) , You need to download the .tax2017 datafile from your prior Online TTX account (not the PDF file), dn place it on your desktop (Windows), or in some known directory, where you can browse to it, after you initiate the start of a new 2018 tax return.
The information it transfers is somewhat minimal, but does transfer names, SSNs, certain needed carryover information, and usually some tax forms that have been emptied of last year's $$ values (2017 in this case)....but ready to receive the next year's information.
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The data transfer must be done right at the very start of a new 2018 tax file...you can'st start one and wait until later to transfer in the 2017 file.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
