The Earthquake Commission is trying to track down $20 million worth of settlement cheques that have not been claimed.
The EQC's financial controller, Chris Chainey, said 3800 cheques have not been cashed, some of which are for more than $100,000.
He said over 2000 cheques are more than six months old and are invalid, but there are still 1600 which are current.
Mr Chainey said it is possible people have moved without the EQC being aware and the cheque has been lost.
He said if people were expecting a cheque that never arrived, they should call the commission and another cheque will be issued or a deposit will be made straight into a bank account.
But Earthquake Services director, Bryan Staples, said he knows of people sitting on cheques because they don't believe the money is enough.
He said it is important people bank the cheque and chase EQC up for the balance.
The EQC has paid over $4.8 billion in cash settlements to Canterbury earthquake claimants.