The cost of damage from today's devastating quake could be as much as $2 billion, Earthquake Commission chief executive Ian Simpson says.

The EQC's claims staff had been flat out taking calls today and there was no data yet on the number lodged, he said.

"It's very early to start estimating the numbers so far," he said.

"At a guess, and it is just a guess so far, we are looking at ...around 100,000 claims in total from the event and the cost will be easily into the hundreds of millions of dollars just for EQC for the residential property... It could reach between one and two billion dollars."

People who had private house insurance were automatically qualified for EQC cover.

EQC paid out a maximum of $112,500 (inc GST) on houses and $22,500 (inc GST) on contents. Any damage above that was usually covered by insurance companies.

"If the loss is higher than that it kicks into their private insurance."

Those with no insurance were not covered by the EQC.

"People who are unsure of their insurance situation, or don't remember who they're insured with, should contact us too. We will do all we can to check their insurance details for them," Mr Simpson said.

Claims would come in from a far wider area than Christchurch and small claims, for example broken dishes, would be expected as well as the more substantial ones.

"What I would say to people is the immediate first step is to look after yourselves and your families, look after safety let the emergency services and then when you are ready to place a claim (do so)."

People had three months to lodge a claim but he advised against waiting too long.

"We would encourage people maybe over the next week would be a good time to place a claim."

Claims could be lodged by calling 0800326243 or online at www.eqc.govt.nz

People should contact EQC personally, rather than getting their broker, agent or insurance company to call, Mr Simpson said.

People should, if possible, take photos before moving anything or tidying up as it made it easier to assess the claim.

"If you are able to, essential services, like toilets and water systems can be repaired but people should keep everything the repairer replaces, and keep a copy of the bill," he said.

"Spillages or crockery and glass breakages can be cleared up, but don't throw anything not perishable away yet. Ruined or spilt food and other perishables can be disposed of, but people should list the items as they bury, burn, or dump them."

AA Insurance deputy general manager Martin Fox said the number of personnel in its call centre had been increased to handle an expected claims surge.

"Our people are all prepared to handle a surge in claims and we're bringing in additional people to help," Mr Fox said.

"AA Insurance is committed to helping our customers get their lives back to normal as quickly and easily as possible."

- NZPA