Certificate of Fitness
A Certificate of Fitness is the periodic safety inspection for heavy vehicles and vehicles used commercially — trucks, heavy trailers, taxis and other passenger service vehicles, and rental vehicles. If you drive an ordinary private car, you do not need one; you need a WoF. The line is drawn by gross vehicle mass and by what the vehicle is used for, and it is use that changes without anyone telling you.
Most people who land on this page do not need a Certificate of Fitness. If you drive a private car, a ute you use for your own purposes, a motorcycle or a light trailer, your vehicle takes a Warrant of Fitness and the rest of this page is background.
A CoF is the equivalent inspection for a different fleet: vehicles that are heavy, or that work for a living carrying people or being hired out. It runs on a shorter cycle, covers more, and is done at a smaller network of sites, because not every garage that issues warrants is appointed to do CoF work.
Who actually needs one
Two things put a vehicle into CoF territory, and either one is enough.
Weight. Vehicles above the light-vehicle threshold by gross vehicle mass take a CoF. The figure that matters is the GVM recorded against the vehicle, not what it weighs loaded on the day, and not what it looks like. A large van and a small truck can sit on opposite sides of that line despite appearances.
Use. Vehicles used to carry passengers for payment — taxis, shuttles, rideshare vehicles, buses — are passenger service vehicles and take a CoF regardless of how ordinary the car is. Rental vehicles take a CoF. Heavy trailers take one. So do certain other classes set out in NZTA's rules.
The full list of classes is on NZTA's Certificate of Fitness page, and it is worth reading against your own vehicle rather than reasoning from a similar one you have seen on the road.
Use is the trap, not weight. Weight is fixed and knowable. Use changes on a decision — the day you start hiring the van out, the day you take your first paying passenger — and nothing in the system prompts you. The vehicle's certification requirement changes at that moment, not when someone eventually asks about it.
How a CoF differs from a WoF in practice
It runs more often. CoF intervals are shorter than WoF intervals, because the vehicles covered are heavier, work harder, or carry the public. The exact interval depends on the vehicle class.
It covers more. The inspection is broader than a warrant, reflecting the systems these vehicles carry and the consequences when they fail.
Fewer places do it. A CoF requires an inspecting organisation appointed for that work, and there are far fewer of them than there are garages issuing warrants. In smaller centres that can mean a real drive and a booking made well in advance rather than a walk-in. Where CoF inspections are done covers finding one.
It costs more. A longer inspection on a bigger vehicle at a specialist site is priced accordingly, and like WoF pricing it is a commercial matter rather than a regulated figure. What a CoF costs sets out what drives the number.
One thing that does not change is the recheck rule. A vehicle that fails gets a free recheck within 28 days at the same inspecting organisation — which can be another branch of the same company, but not a different company. After 28 days it is charged as a new inspection. On a heavy vehicle with parts on order, that window closes faster than people expect.
The changes to inspection frequency taking effect on 1 November 2026 are changes to light vehicle inspections. They alter WoF frequency bands. If your vehicle runs on a CoF, its inspection cycle is not affected by them.
If you have been running the wrong certificate
This happens, and it is usually honest. Somebody buys a vehicle that turns out to be over the threshold, or starts using a perfectly ordinary car for paid work without realising the certification follows the use.
A warrant issued to a vehicle that should hold a CoF does not make its use legal. The label in the windscreen is not the point; the certification the vehicle is required to hold is. So the fix is to get the vehicle certified properly rather than to rely on the paperwork you already have.
Practically, that means finding an inspecting organisation appointed for CoF work, booking in, and expecting the vehicle to be inspected against the CoF standard rather than having a piece of paper corrected. Budget for the possibility that it does not pass first time, because the standard is broader than the one it has been meeting.
Working out which side of the line you are on
- Find the vehicle's recorded gross vehicle mass
Not an estimate and not the kerb weight. It is recorded against the vehicle, and it is the figure the classification uses.
- Describe the actual use honestly
Private, goods for your own business, goods for hire, passengers for payment, rental. The last three are the ones that change the answer.
- Read the classes against the vehicle
NZTA's CoF page lists them. WoF or CoF walks through the same decision in more detail if the answer is not obvious.
- Check what is currently recorded
Checking the WoF status against the plate tells you what certification the vehicle currently holds and when it runs out, which is a useful reality check on what you assumed.
- Ask before the vehicle goes into new use
If the vehicle is about to start earning, confirm the requirement with NZTA first. This is much cheaper as a question than as a discovery.
If it turns out your vehicle takes a warrant after all — which, for most people reading this, it does — the Warrant of Fitness overview covers frequency, scope and what happens when one lapses.
Frequently asked questions
Do I need a Certificate of Fitness for my car?
What is the difference between a WoF and a CoF?
Do I need a CoF for rideshare or taxi work?
How often is a CoF inspection?
What happens if my CoF expires?
Sources and verification
- NZ Transport Agency Waka Kotahi. Warrant of Fitness, checked 2026-08-12.
- NZ Transport Agency Waka Kotahi. Official vehicle and driver licensing information, checked 2026-08-12.
- NZTA Vehicle Inspection Portal. In-service WoF and CoF — inspection and certification process, checked 2026-08-12.
- New Zealand Police. Grace periods and infringement fees for expired rego or WoF, checked 2026-08-12.
Checked against the sources above. If something has changed, tell us.