If he used TurboTax online, you will need the User ID and password he used to access the TurboTax online account.
You will have to contact TurboTax support for assistance with this problem.
See this TurboTax support FAQ for contacting support - https://ttlc.intuit.com/turbotax-support/en-us/help-article/account-management/turbotax-phone-number...
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax
