Can I put my new hire on a 90-day trial period — and what makes it stick?

Reference guide from Amplifai — the structured AI workspace for NZ business decisions.

Guide · Hiring & employment

The short version

Most employers who use trial periods invalidate them by accident — and only find out when they actually need the protection. About three out of four trial-period dismissals taken to the Employment Relations Authority over the last decade failed.¹ Almost all of them on procedure, not on the underlying call. So the question isn't whether you can use a trial period — every NZ employer can.² The question is whether the one you've drafted will actually hold up.

This guide tells you what makes a trial period stick, the six places employers most often blow it, and where you should stop reading and call a lawyer.

Where to find the authoritative answer

Four places worth knowing about. Each one does a different job.

Employment New Zealand — Trial periods. Government / authoritative. The operational guide on eligibility, drafting, and how to dismiss during a trial. Start with their "Who can use a trial period" section. Most employers go wrong before they've even hired anyone.

business.govt.nz — Employment Agreement Builder. Government / tool. Free, interactive, produces an agreement with a properly-worded trial provision. Use this rather than a Word template off the internet — manually-drafted clauses are a common reason trials fail.

The trial-period sections of the Employment Relations Act. Statute / public domain. The actual law. Worth a read if you're going to rely on the protection — the requirements are sitting right there in the text.

Immigration NZ — AEWV and 90-day trial periods. Government / authoritative. If you're hiring on an Accredited Employer Work Visa, you can't use a trial period at all. This is the primary source on that.

What to watch for

Six places trial periods go wrong.

1. Signed before the employee starts work — not on day one. This is the single most common procedural failure. The agreement, with the trial clause in it, has to be signed before the employee does any work for you. A signature collected on the morning of day one, after they've shown up, is too late. Email exchanges, "we'll sort the paperwork on Monday," verbal agreement on the phone — none of that gets you there.³

2. The clause has to specify a number of days, not a number of months. "Three months" instead of "90 days" has invalidated trial periods. Three months is longer than 90 days, even by a day or two, and that's enough to fail the wording requirement. Use the day count.⁴

3. AEWV migrant workers can't be on a 90-day trial at all. Since late October 2023, accredited employers cannot use trial provisions in employment agreements for anyone hired on an AEWV. Easy to miss, high consequence — including potential loss of accreditation. If you hire migrants under AEWV, your standard agreement template needs the trial clause stripped out for those hires.⁵

4. "New employee" means new to you. A trial provision is only valid if the employee has not previously worked for you. That includes the gotcha cases: a contractor a court might later reclassify as having been an employee, someone who did a paid trial shift before signing, someone who briefly held a different role with you years ago. If there's any prior working relationship, the trial provision can be invalidated on those grounds alone.⁶

5. Notice during the trial has to be given before day 90, even if it lands after. If you decide to dismiss, you give notice — and that notice has to reach the employee while the trial period is still running. Notice given on day 91 invalidates the trial-period defence, even if the dismissal itself was for fair reasons. This trips employers up when they leave the call to the last weekend.

6. The employee needs reasonable time to seek independent advice before signing. Sliding the agreement across the desk on Friday afternoon for a Monday start, without flagging that they can take advice, has been used to invalidate trials. Build a couple of working days into your offer-to-start timeline and tell the candidate in writing that they're welcome to take legal advice.

7. A "probationary period" is not a trial period — and the dismissal protection only flows from the statutory mechanism. Section 67B removes the employee's right to bring a personal grievance for unjustified dismissal only where a valid trial period under section 67A is in place and the dismissal occurs within it. A probationary period — a contractual label without a statutory definition — carries none of that protection. The standard dismissal obligations apply from day one: a genuine reason, a fair procedure, an opportunity for the employee to respond. An employer who dismisses within a "probationary period" and finds out it wasn't a valid 90-day trial is in the same position as an employer who dismissed without one — full personal grievance exposure. The gap typically enters through recycled templates: agreements written for one context, copied across, with "probationary period" where the statutory term "trial period" should appear. If you're not certain which term your current agreement uses, read the clause before the hire is made, not after you need it.

A separate point on what trial periods are for. Most employers who include them never use them to dismiss — they're a backstop for the rare hire that turns out to be catastrophic. Used that way, they reduce the risk of taking a chance on someone. Treated as a cheap fire mechanism, they don't work — the procedural bar is too strict, good faith still applies, and the trial protects you against unjustified-dismissal claims only. Discrimination, harassment, breach of statutory entitlements — all still on the table.

The more you hire, the more the backstop compounds. The procedural bar is fixed cost — get the signed-before-day-one discipline right once, build it into the offer process, and it holds on every hire. A high-churn operation runs that exit mechanism constantly; clean template discipline is the difference between a clean exit every time and exposure on every one.

Where this entry stops

This entry covers whether you can use a trial period, what makes it valid, and where the procedure usually breaks. It doesn't cover:

Dismissal procedure during the trial in detail. If you're considering dismissing someone and you're not certain the trial is valid, stop and get advice before acting. The cost of a wrongly-invalid trial leading to a successful personal grievance is much higher than half an hour of lawyer time. See the entry on personal grievance reforms.
Probationary periods — the full mechanics. The distinction between a probationary period and a 90-day trial is in watch-for #7 above. The full process for managing performance or ending a probationary arrangement sits outside this entry — the same fair-process framework that governs any dismissal applies. If you're contemplating ending a probationary arrangement, get employment-law advice before acting.
Trial periods inside collective agreements. Different rules apply. Defer to the collective agreement and to specialist advice.

If you're hiring under AEWV, in sector-specific arrangements (rural, hospitality, healthcare, construction labour-hire), or anywhere the prior-employment question is murky — get proper advice before the agreement goes out, not after.

Last verified 9 June 2026. Full source list: references.