To merge duplicate student accounts, review both accounts created in the All Students tab and decide which account will be the "destination" account - this is the one that will have information merged into it and will become the consolidated record.
Once you've decided which account to keep, locate the Internal ID on the Student Details tab, and copy it.
Exit this student record and open the details for the account that will ultimately be merged and deleted. On the Migrate Record tab, paste the Internal ID you copied from the destination account. The details for the destination account will display on the right side of the screen for verification. Select the Items to Move from the account being deleted, and click Submit.