Claims & Accidents

Who Is at Fault in a Car Accident NZ? Understanding How Fault Is Determined

By InsurspyPublished 4 October 2025

Introduction

After a car accident in New Zealand, the short answer is that fault is assessed from the facts, the applicable road rules and the evidence—not from a simple label attached at the roadside. A driver’s breach of a road rule can be important evidence, but causation and each person’s conduct still matter. For vehicle and other property damage, insurers make claim and recovery assessments; an assessment is not necessarily the final word on civil liability.

This is general information, current as at 17 August 2026, rather than legal or personalised insurance advice. Our team recommends preserving evidence and checking your own policy wording before making assumptions about cover, excess or repair costs.

How fault is assessed after a crash

Fault questions commonly start with what each road user did immediately before the collision. Relevant material can include the positions and damage to vehicles, photographs, dashcam footage, witness accounts, driver statements, road layout, signs, markings and any Police information.

Road rules provide an important framework. Drivers must comply with stop and give-way signs. Rules also require drivers who are turning or changing lanes to give way to vehicles that are not turning or changing lanes, and specific intersection rules can apply. A breach may strongly support an allegation of fault, but it does not remove the need to establish how the breach caused the loss and whether another person’s actions also contributed.

For example, a rear-end crash, reversing collision, lane-change crash or intersection crash should not be treated as automatic proof that one particular driver is liable. The evidence, visibility, movements, road conditions and applicable rules need to be considered in the individual case.

Can responsibility be shared?

Yes. Where damage was caused partly by one person’s fault and partly by another’s, the Contributory Negligence Act 1947 allows a court to reduce damages to the extent it considers just and equitable. That is not a standard insurer percentage split: the outcome depends on the evidence and circumstances.

Vehicle doors are not only a driver issue

The Road User Rule prohibits a person from causing a hazard by opening or closing a motor-vehicle door, or by leaving one open. This means responsibility in a door-related collision is fact-dependent and is not confined automatically to the vehicle’s driver.

Who has a role in deciding fault?

Different bodies have different jobs. Police may attend or investigate matters involving safety, enforcement or potential criminal issues. Insurers assess claims and may seek recovery from another party. If a civil liability dispute remains unresolved, it may be addressed through agreement, the Disputes Tribunal or the courts. A consumer who disputes their own insurer’s handling should use the insurer’s complaints process first.

In our editorial review, the practical distinction is important: a Police response, an insurer’s claim decision and a civil liability outcome are not interchangeable. Give truthful, factual information to Police and your insurer; do not speculate or make assumptions about what caused the crash.

What to do at the scene

Your immediate obligations and safety come first. A driver involved in an accident must stop, check whether anyone is injured and give all practicable assistance to injured people.

Priority	Practical action	Why it matters
Safety and injury	Stop, assess injuries and provide practicable assistance. Call 111 if Police attendance is needed at the scene or anyone is injured.	Protects people and helps meet immediate legal duties.
Information	If required by an enforcement officer or another person involved, provide your name and address, electronic address if you have one, owner details and vehicle registration information.	Helps identify the parties and supports later communication.
Evidence	When safe, photograph vehicles, damage, the wider scene, signs, lane markings and road conditions. Record witness contact details and preserve original dashcam footage.	Contemporaneous evidence can clarify competing accounts.
Reporting	Report an injury or death crash to an enforcement officer as soon as reasonably practicable and no later than 24 hours, subject to the statutory incapacity exception. For unattended property damage, owner-reporting and Police-reporting time limits apply.	Reporting duties vary with the circumstances.
Insurance	Notify your insurer in line with your policy and provide an accurate account and relevant evidence.	Policy conditions and claims processes can affect how the claim proceeds.

For a non-injury crash, NZ Police provides a traffic-crash reporting option. If another vehicle leaves the scene, focus on safety, record any available registration, vehicle description and witness details, preserve evidence, and notify Police and your insurer as appropriate.

Fault, ACC and car insurance are different questions

ACC operates a no-fault scheme for people injured in an accident in New Zealand, regardless of who was at fault, provided the injury is within ACC legislation. ACC may help with eligible treatment, recovery support and, where applicable, income support. It does not decide responsibility for vehicle repairs or other property damage.

Property-damage cover depends on the policy. Comprehensive insurance can cover accidental damage to the policyholder’s vehicle as well as damage to other people’s property. Third-party insurance generally covers liability for damage to others’ vehicles or property, rather than accidental damage to the policyholder’s own car. Terms, exclusions and eligibility differ between policies. When we compare policy information, we look beyond the cover label and recommend that readers do the same. See our car insurance information for a starting point when comparing cover types.

Excess and renewal effects

Do not assume that an excess will always apply, be waived, or be refunded. Consumer Protection notes that some policies may waive or refund excess for a not-at-fault collision where the driver can establish lack of fault and obtain the other driver’s name, address and telephone number. This is conditional and policy-specific. No-claims discounts and renewal pricing are also determined under the relevant policy and insurer pricing approach.

How to challenge a disputed insurance decision

Ask for the reasons. Request the insurer’s explanation of its decision and identify the evidence it relied on.
Respond with focused evidence. Provide missing photographs, original footage, road-layout information, witness details or a clear chronology. Keep copies of what you send.
Use the internal complaints process. Set out the outcome you seek and why the available evidence supports it.
Escalate to the correct approved scheme if needed. Retail financial-service providers must belong to an approved dispute-resolution scheme. If the matter remains unresolved after the insurer’s process, seek a free, independent view from the scheme named by that insurer.
Consider the appropriate civil route. If the dispute is about liability between parties rather than the service of your own insurer, agreement, the Disputes Tribunal or the courts may be relevant. Consider legal advice for complex matters.

IFSO is one approved scheme, but it is not automatically every motor insurer’s scheme. Other approved schemes include FSCL, FDRS and the Banking Ombudsman Scheme. Check the details your insurer provides rather than directing a complaint to a scheme by assumption.

Practical Takeaway

Do not decide fault from the collision type alone; gather evidence and identify the relevant road rule.
Put safety first, meet reporting and information duties, and give accurate facts to Police and your insurer.
Separate injury support from property damage: ACC’s no-fault injury cover does not resolve vehicle-damage liability.
Read the policy wording before assuming your own vehicle is covered or an excess will be waived.
If you dispute your insurer’s decision, use its complaints process first, then its named approved dispute-resolution scheme if necessary.

References

Author / Editorial Team

This article was produced by Insurspy’s internal editorial and research team. In our editorial review, we prioritise authoritative New Zealand legislation, government guidance and regulator information, and review insurance content for accuracy, clarity and practical usefulness. Information is general in nature; policy wording, eligibility and individual circumstances can change the outcome.

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