If their current amount of superannuation left floating around in the Australian Tax Office's bank is anything to go by, it'll be those who live in the area with a postcode of 2615.

New data from the ATO shows that residents from 12 west Belconnen suburbs - including Latham, Florey and Macgregor - were yet to claim $26 million out of the territory's $222.5 million in lost super.

People who have the postcode 2602 - which includes Ainslie, Dickson, Downer, Hackett, Lyneham, O'Connor and Watson - were the second most forgetful, with about $19 million yet to claim.

Coming in third place were the residents of the Gungahlin postcode 2913, who have about $17 million in lost super. This includes Nicholls, Ngunnawal, Kinlyside, Franklin, Casey, Taylor and Palmerston.

Super contributions are made by employers and can be topped up by the employee.

The money is considered ''lost'' when a fund cannot contact the person and has not received a contribution to an account for five years.

Deputy Commissioner James O'Halloran said 43 per cent of Australians have several super accounts and that many were oblivious to fees eating away at their funds.

"A lot of people who worked casually while they were studying or worked multiple part-time jobs find super they had completely forgotten about," he said.

"Members often lose contact with their super funds when they change jobs, move house, or forget to update their details."

Mr O'Halloran said updating super fund details was a last priority for many people, but emphasised it was important to ensure each super fund has a correct tax file number on record so that it can be found later on.

"You might choose to keep multiple accounts, but to save on fees and charges, consider consolidating your multiple super accounts online into the one you prefer," he said.

To find lost and unclaimed super, visit www.ato.gov.au/checkyoursuper