There are many reasons why employees leave, and you will need to include the reason in your STP report. Cessation reasons you can report are as per the ATO's STP2 Definitions l
Voluntary Cessation An employee resignation, retirement, domestic or pressing necessity or abandonment of employment.
Ill Health An employee resignation due to medical condition that prevents the continuation of employment, such as for illness, ill-health, medical unfitness or total permanent disability.
Deceased The death of an employee.
Redundancy An employer-initiated termination of employment due to a genuine bona-fide redundancy or approved early retirement scheme.
Dismissal An employer-initiated termination of employment due to dismissal, inability to perform the required work, misconduct or inefficiency.
Contract Cessation The natural conclusion of a limited employment relationship due to contract/engagement duration or task completion, seasonal work completion, or to cease casuals that are no longer required.
Transfer The administrative arrangements performed to transfer employees across payroll systems, move them temporarily to another employer (machinery of government for public servants), transfer of business, move them to outsourcing arrangements or other such technical activities.
Review the ATO Employer reporting guide for more information: