Almost $18 billion of lost super is waiting to be claimed, with Sydney's Liverpool, Campbelltown, Surry Hills, Darlinghurst and Bondi featuring among the top 10 locations nationally for unclaimed funds.
As at June 30, the Australian Tax Office held records of more than 6 million lost and unclaimed accounts.
Mackay and Cairns and surrounding areas have the most lost super nationally. Each area has more than $60 million in lost super.
Melbourne's Werribee and Cranbourne also feature in the top 10 list.
Super becomes lost because, among other causes, members change jobs or addresses without telling their funds.
Super funds are holding more than $14 billion of lost super, while a further $3.75 billion of unclaimed super is held directly by the ATO.
Over half the amount of lost super held by super funds, $7.6 billion, belongs to people aged 40-55.
Super funds have to inform the ATO of lost accounts so that it can use its extensive data-matching powers, including tax file numbers, to find the owners.
A super account is deemed "lost" if the fund cannot make contact with the account owner and there is no activity on the account.
Lost super accounts with less than $6000 in them are automatically transferred to the ATO.
The reason is that some super funds charge high fees on lost accounts, which can quickly eat into small accounts.
There are no fees on the accounts held by the ATO and the accounts earn the rate of inflation.
The easiest way to search for lost or unclaimed super was by using the ATO's online services through myGov, said Debbie Rawlings, an ATO assistant commissioner.
"Over the past four financial years, we've reunited 1.68 million accounts worth $8.12 billion with the account owner, and there's plenty more to be found," Ms Rawlings said.
To find out how to manage your super and view all your super accounts, including lost and unclaimed super accounts, visit www.ato.gov.au/checkyoursuper.
Alternatively, you can call the ATO Super Helpline on 13 10 20.
