There are almost six million 'lost' superannuation accounts with a value of $11.7 billion, new Australian Taxation Office figures show.

There are now 5.9 million 'lost or inactive' accounts totalling $11.65 billion for 2015-16, down from 13.9 million accounts in 2014-15.

The ATO says $2.5 billion worth of super money was consolidated into active super accounts during 2015-16. Credit:Michel O'Sullivan

Super is considered 'lost' when a fund is unable to contact the individual and hasn't received a contribution to an account for five years.

The ATO says members often lose contact with their super funds when they change jobs, move house, or forget to update their details.