I'll tell you below how to look for multiple accounts and restore access.
As I said above, hopefully you used separate accounts for 2017 for the son's return and your return.
If you prepared the 2017 return online and can't find it when you log into the son's account, go to the Tax Home and look in the section "Your Tax Returns & Documents, then you likely have multiple accounts (User IDs) without realizing it and
signed into the wrong one. This is one of the more common questions in
You can have up to 5 accounts that use the same
email address for notification purposes. A User ID may be an email
address, but it doesn't have to be. It might be only part of an email
address, or it can be anything at all.
NOTE: Before running the account recovery tool below, log out of all Intuit accounts including this user forum, or you might end up in a loop. Then clear your browser Internet cache, close your browser, then reopen it, and go to the link below. You may wish to copy this link so you can paste it into the new browser session.
If still no luck after running that on your phone number and email address(es) that you can access, here's another method.
Go back to the tool again, but this time leave the data field blank, and choose the small blue link that says "Try something else", and it will look you up by SSN and other parameters.