More details have emerged of the government's plan to use money in dormant bank and building society accounts for community projects.
The Treasury wants good causes to benefit from unclaimed cash
The Treasury said cash from bank and building society accounts which have seen no activity for 15 years would be transferred to a central fund.
However, money will be set aside in case people whose money has been transferred to the fund want it back.
Analysts have said that up to £400m could come from dormant accounts.
What is more, a further flow of tens of millions of pounds may become available each year as more accounts become dormant.
Dormant account cash will be used to fund a host of community projects, Ed Balls, economic secretary to the Treasury, said when launching a consultation document on the subject.
"This is a unique opportunity to provide for worthwhile reinvestment in youth services, financial inclusion and capability, while balancing the financial interest of consumers," Mr Balls said.
The idea of using dormant account cash for community projects was first mooted in the 2005 pre-Budget report.
Banks and building societies have pledged to try to reunite customers with their dormant account cash before the money flows into the central fund to be distributed.
Last month, the Halifax bank said it would advertise to alert holders of 110,000 dormant accounts, containing deposits worth £44m, to the potential threat to their cash.