The Insurance Council says some insurers might not let customers in Canterbury take out new insurance policies because of fears people might dishonestly claim earthquake damage.
But at least one company, AA, says it will still sign people up.
The council's chief executive, Chris Ryan, says many companies have put a hold on new policies to stop people from buying damaged cars and then claiming they were damaged in an aftershock.
Mr Ryan says the hold is normal practice in the industry. He suggests people hold off buying a new car until it is over.
AA Insurance says, however, that it is still granting new policies and is trusting people to be honest when they take out insurance in Christchurch.
Mobile insurance vans
AA and SIS insurance companies are using vans to process claims in quake-affected parts of the city.
The companies say their "mobile claims centres" can organise temporary accommodation, emergency grants for clothing, toiletries and frozen food.
They can also arrange a rental car for people whose vehicles are damaged or trapped in the central business district.
The companies say people do not need any paperwork to make a claim - just ring 0800 339 539 to find out when a van will be in your area.