Car accident lawyer, Len Waters Estate: who was at fault?

The insurer that decides fault will not have been there. It relies on what people recorded at the time. So record what you can: the time, the weather, the road surface, the lane markings and the direction each vehicle was travelling. If a witness stopped, ask whether they'll give their name. A note written that evening is worth more than a memory months later.

• What the traffic lights or give-way signs showed
• Skid marks, debris and the damage to each vehicle
• Names and phone numbers of anyone who saw it
• Whether you and your passengers wore seatbelts

Chain collisions are where fault gets complicated. The driver who started it may carry most of the blame, but a driver behind who was following too closely can share it. Each vehicle has its own Green Slip insurer. Your task is to record every vehicle involved and the order of the impacts; the insurers' task is to sort out which of them responds.

The police event number is often the thread that ties a multi-vehicle crash together. It links the drivers, the vehicles and any statements taken at the scene. Keep it with your registration notes. CTP Assist, a free SIRA service on 1300 656 919, can help identify an insurer when you're unsure, though it won't decide fault for you.

Fault is decided on evidence, not on who sounds more certain. The usual pieces are the police event number and any police record, photos of where the cars stopped, the damage to each vehicle, dashcam footage and independent witnesses. No single piece is always decisive. Together they usually show what happened, even when the drivers tell different stories.

The police event number links your claim to the official record of the crash. The insurer can use it to check who was involved and what was reported. It's worth getting even if the crash seemed minor and police didn't attend, because a record made close to the time is harder to dispute than one pieced together later.

• Dashcam footage, saved as the original file
• Photos of both vehicles' damage and final positions
• Photos of signals, signs and lane markings
• Any messages the other driver sent after the crash

A seatbelt argument is the classic example. If the insurer says your injuries were worse because you weren't belted in, it may reduce what you receive. The percentage isn't set by a formula. It's argued on the evidence, including medical opinion about how each injury happened, which makes it worth checking rather than simply accepting.

Think of the claim in two parts. Statutory benefits come first and, for most people, don't depend on who caused the crash. Common law damages come later and depend heavily on it: another driver must have been at fault, you must not have been mostly at fault, and the injury must be more than a threshold injury. That is why fault is worth attention early.

Being a passenger doesn't make fault irrelevant. It shifts the question to the drivers. If the driver of your car and another driver both contributed, your claim may involve both vehicles' insurers. Your own conduct can still come up in limited ways, such as not wearing a seatbelt or travelling with a driver you knew was affected by alcohol.

Passengers in a crash between two cars sometimes find that each driver blames the other and neither insurer will accept the claim at first. You don't have to take sides. Give an honest account of what you saw, lodge on time, and let the fault question be worked out between the insurers. If it stalls, that's when advice helps most.

A fault finding isn't final just because the insurer has made it. Most insurer decisions can go to internal review, generally within 28 days of receiving the decision, and then to the Personal Injury Commission. Before you accept a finding that you were mostly at fault, have someone look at whether the evidence supports it, because so much turns on that line.