Reference: Supported Person Type Combinations for Merge

You can merge source and target records for combinations of person types. In the hierarchy of supported person-type combinations for merge, the person with the higher-ranked person type is the target.

Source	Target
Candidate	Active Employee and Future-dated Employee
Candidate	Candidate (Workday selects the Candidate who has been in the tenant for the longest time as the target.)
Candidate	Contingent Worker (Active Contingent Worker, Future-dated Contingent Worker, and Inactive Contingent Worker)
Candidate	External Student
Candidate	Former Worker
Candidate	Matriculated Student
Candidate	Pre-hire
Candidate	Student Prospect
Candidate	Terminated Employee
External Student	Active Employee and Future-dated Employee
External Student	Contingent Worker (Active Contingent Worker and Future-dated Contingent Worker)
Matriculated Student	Active Employee and Future-dated Employee
Matriculated Student	Contingent Worker (Active Contingent Worker, Future-dated Contingent Worker, and Inactive Contingent Worker)
Matriculated Student	Student Prospect + Worker
Pre-hire	Contingent Worker (Active Contingent Worker, Future-dated Contingent Worker, and Inactive Contingent Worker)
Pre-hire	Employee (Terminated Employee only)
Pre-hire	External student
Pre-hire	Former worker
Pre-hire	Matriculated Student
Pre-hire	Pre-hire (Workday selects the pre-hire who you entered first in your tenant as the target.)
Pre-hire	Student Prospect
Student Prospect	Active Employee and Future-dated Employee
Student Prospect	Contingent Worker (Active Contingent Worker, Future-dated Contingent Worker, and Inactive Contingent Worker)
Student Prospect	External Student
Student Prospect	Matriculated Student
Student Prospect	Student Prospect
Student Prospect	Terminated Employee

Merging Person Types with System Accounts

Specific merge rules apply to these person type combinations with Workday system accounts:

Source	Target
External Student	Contingent Worker
External Student	Employee
External Student	Terminated Worker

When merging these person type combinations with Workday system accounts, consider:

Source	Target	Merge Description
Active system account	Active system account	Workday prevents the merge because the source is active.
Active system account	Inactive system account	Workday prevents the merge because the source is active.
Inactive system account	Inactive system account	Workday merges the accounts and retains the target system account.
Inactive system account	Active system account	Workday merges the accounts and retains the target system account.
No system account	Active system account	Workday merges the accounts and retains the target system account.
No system account	Inactive system account	Workday merges the accounts and retains the target system account.
Active system account	No system account	Workday prevents the merge because the source is active.
Inactive system account that was never accessed	No system account	Workday merges the records and moves the source account to the target.
Inactive system account that was accessed in the past	No system account	Workday merges the records, but doesn’t move the source account to the target.