Do you have to include leave loading in an employee's final pay?

The short answer is yes.

If an employee would have received an annual leave loading at the time of taking annual leave, then you must pay that out as part of the employee's final pay on termination of employment.

What's more, the Fair Work Ombudsman says, 'annual leave loading is paid out even when an award, registered agreement or employment contract says that it’s not.'

Of course, if the employee was not entitled to leave loading while employed then it would not be paid out when they leave.