To set the ATO Credential in the current year of HandiTax:
Open HandiTax, then go to Lodgment, Set ATO Credentials.
Under Browse for Key Store file, click the ellipsis to select, and then click Open.
From the Select Credential drop-down menu, select your credential.
Enter your keystore password.
Click Ok.
Restart HandiTax for the changes to take effect.
When you next log in, attempt a prefill or lodgment to check that the credentials function successfully.
Note: Ensure you have notified the ATO of your Software ID.