Irish Water is appealing for people to contact them if their circumstances have changed in order to receive their refunds.
Refunds will start being processed in the coming weeks, once the Government passes the necessary legislation.
One million households that paid their bills will receive cheques for up to 325 euro, depending on how many bills they paid.
Despite a commitment by the Government that people would be refunded by Christmas, some refunds may be delayed until the New Year.
If your details have changed however you are asked to contact Irish Water.
Richard O hEadhra from Irish Water spoke to Kerry Today:
Irish Water has this advice for the next of kin of account holders who have passed away: