How can I unlock the 2017 .tax file for amending? I already have purchased the 2017 and 2018 desktop versions.

In TurboTax Free Edition, you can purchase PLUS to unlock your prior-year .tax file.

The exact instructions will vary depending on the status of your 2018 TurboTax Online return (select one):

• I haven't started a 2018 return yet
• I started a 2018 return but haven't filed it yet
• I've already filed my 2018 return

However, since you have purchased the 2017 desktop edition you should contact TurboTax support and speak to an agent to see if they will let you access  the 2017 online account and download the tax data file at no charge.

Support is open from 5am to 5pm Pacific time, Monday thru Friday

Use this website to contact TurboTax support during business hours - https://support.turbotax.intuit.com/contact/
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax