Irish Water is preparing to issue one million refunds in the coming weeks.
The utility is advising customers who’ve moved house to contact them with their new address. They've also launched a refunds page on its website for those who're due money back.
For the most part, customers won’t have to do anything to get their money back but if your circumstances have changed recently, they're urging you to get in touch.
"For the large majority of customers, they won't need to take any action", says Yvonne Cahill from Irish Water.
"Irish Water will issue cheques to the account holder at the address which we have on file, which is largely where the bill was sent to".
Last month customers were told that they'd be repaid the full amount of their water charges before the end of the year.
The Govt is expected to enact legislation allowing refunds by the end of the month, with refunds due shortly after.