If you have an instance of duplicate user accounts for a person, you can use the option 'Merge People' in People Management to ensure they only have one user account.
Generally this is used to merge duplicate user accounts with the same role type, student/student, parent/parent or staff/staff but if needed, can be used to merge duplicate user accounts that have different role types i.e. a parent account into a staff account.
To merge user accounts, you will require the UserRecordsAdmin permission.
For details on assigning permissions in Compass, please refer to the 'Permissions' article from our Knowledge Base.
Go to People Management under the Organisation menu (grid icon).
Use the filter options to locate the two accounts for the user and tick to select them.