90 Day Trial Period Checker NZ 2026
A 90 day trial period lets an employer dismiss a new employee within the first 90 days without that dismissal being challengeable as unjustified. It is a genuine exception to the ordinary rules, and because it is an exception the conditions are strict and applied strictly. The overwhelming majority of trial periods that fail do so for one reason: the employee started work before signing the agreement. Turning up on the Monday and signing the paperwork on the Tuesday is enough to void the clause entirely, and no amount of good faith afterwards repairs it. The other point worth understanding is how narrow the protection is even when everything is done correctly. A valid trial period stops one specific claim. It does not stop a discrimination claim, a harassment claim, or a claim for wages that were never paid, and it does not remove the notice provisions in the agreement.
Condition by condition
Every condition must be met. Any row marked not met voids the trial period on its own.
| Condition | Result |
|---|
What a valid trial period does and does not bar
| Claim | Barred by a valid trial? |
|---|---|
| Personal grievance for unjustified dismissal | Yes |
| Discrimination | No |
| Harassment, including sexual harassment | No |
| Unjustified disadvantage that is not the dismissal | No |
| Unpaid wages or holiday pay | No |
| Breach of the notice provisions in the agreement | No |
Signing before the first day is the whole ballgame
The requirement is that the employee agrees to the trial period in writing, in good faith, before they start work. Employers lose this constantly and rarely deliberately. A verbal offer is accepted, a start date is agreed, the employee turns up keen on the Monday, and the paperwork is signed at some point during the first week because everyone is busy. That sequence voids the trial period. So does an employee doing any work at all, including a paid induction or a half day of training, before the agreement is signed. The fix is procedural and costs nothing: send the agreement, get it signed and dated, and only then confirm the start date.
Ninety calendar days is shorter than it sounds
The period runs in calendar days from the first day of work, so weekends, public holidays and any leave all count against it. Ninety days is about thirteen weeks, and an employer who plans a review at "three months" is cutting it fine, because three calendar months from the start date can fall after day 90. Notice must be given inside the period, not merely decided inside it, and an employer who gives notice on day 91 has an ordinary dismissal on their hands with none of the process they would have followed had they known.
The protection is narrower than most people believe
A valid trial period does one thing: it prevents a personal grievance for unjustified dismissal. Everything else survives. An employee dismissed during a valid trial can still bring a discrimination claim if the reason was their ethnicity, pregnancy, union membership or any other prohibited ground. They can still bring a harassment claim. They can still claim unpaid wages or holiday pay. They are still owed notice under the agreement. Employers who treat a trial period as a general immunity are frequently surprised, and employees who assume they have no rights at all are usually wrong.
Worked example
An employee starts work on Monday 2 March 2026 under an agreement with a 90 day trial period, and notice is given on 15 May 2026. The trial runs to Saturday 30 May 2026, so notice was given inside the period with 15 days to spare, and the length and written form are both fine.
But the agreement was signed after the employee had already started work. That single failure makes the trial period invalid regardless of everything else being correct. The dismissal now has to stand or fall on the ordinary test of justification, and because the employer believed no process was required, it very likely will not.
How this is calculated
The last day of the trial is the first day of work plus the trial length in calendar days, minus one, because the first day counts as day one. Notice is in time if the date given falls on or before that last day. The trial is valid only if every condition is met: the clause is in a written employment agreement, it was signed before the first day of work, the employee has not worked for the employer before, the period is no longer than 90 calendar days, and notice was given within the period. Any single failure voids the trial, so there is no partial credit.
Official sources
- Trial periods, Employment New Zealand
- 90 day trial periods extended to all employers, Employment New Zealand
- Employment Relations Act 2000, legislation.govt.nz
- Trial and probation periods, business.govt.nz
Related NZ calculators
- Personal Grievance Compensation Calculator if the trial period fails
- Notice Period Calculator for the notice still owed
- Final Pay Calculator for everything owed on the last day
- Unpaid Wages Checker for wages never paid
- $200k Personal Grievance Threshold Checker for high income earners
This page explains how the law works and estimates figures from what you enter. It cannot tell you what will happen in your situation, because employment outcomes turn on facts, evidence and the wording of your own agreement. Nothing here creates a lawyer and client relationship.
It has not been reviewed by a lawyer. The legal descriptions are drawn from Employment New Zealand, MBIE and Inland Revenue and were checked against those sources on 7 August 2026. They are our reading of published guidance, not a practitioner's opinion, and parts of this area are very new: the Employment Relations Amendment Act 2026 has been in force only since 21 February 2026 and there is little case law on how it will be applied.
A dismissal may be challengeable even where a trial period looks valid, and the 90 day window to raise a grievance runs regardless. Do not wait for certainty about the trial before taking advice.
Before you act, get advice. A community law centre is free. Employment New Zealand provides free information and mediation. An employment lawyer will tell you things no calculator can. Time limits are short and unforgiving: a personal grievance must generally be raised within 90 days, so seek advice early rather than waiting for certainty.
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How to check whether a 90 day trial period is valid
- Check the agreement was signed first. The written employment agreement containing the trial clause must be signed before the employee starts work.
- Check the employee is new. The employee must not have worked for that employer before, in any capacity.
- Enter the start date. The trial runs 90 calendar days from the first day of work, not 90 working days.
- Check when notice was given. Notice must be given within the trial period, not after it ends.
- Read what it bars. A valid trial bars an unjustified dismissal grievance only. Other grievances remain available.