90-day trial period

The validity conditions that keep failing

Trial period clauses are enforced strictly against the employer, and most that fail, fail on formalities: the clause must be in the written employment agreement, agreed and signed before the employee performs any work, and it cannot be used for anyone who has previously worked for the employer. An employee who starts Monday morning and signs Monday afternoon has no valid trial period. Notice of dismissal must also be given within the 90 days, in accordance with the notice provisions of the agreement.

What a trial period does and does not protect

A valid trial bars a personal grievance for unjustified dismissal (a position the Employment Relations Amendment Act 2026 reinforced), and the employer is not obliged to give reasons for the dismissal. It does not bar grievances for discrimination, harassment or unjustified disadvantage, and the duty of good faith continues to apply throughout. A trial-period dismissal executed with hostility or misleading conduct can still generate a claim through those other doors.

Trial period versus Australian probation

The instruments are cousins but not twins. An Australian probation period is contractual and does not change statutory rights, which flow from the six-month (or twelve-month) minimum employment period regardless. A New Zealand trial period is itself the statutory mechanism, and its protection is stronger while it is valid but entirely dependent on the paperwork being right. In both countries the deeper truth is the same: the trial exists to catch selection mistakes, and better selection is cheaper than either legal instrument.