Customers are being urged to use a new free website to reclaim hundreds of millions of pounds of dormant savings.
The website brings together three separate existing schemes
Mylostaccount.org.uk will let consumers trace forgotten or abandoned bank, building society or National Savings and Investment (NS&I) accounts.
Industry estimates suggest up to £1bn could be dormant.
The site is launched ahead of a government scheme to reinvest "genuinely unclaimed" assets in community projects.
In the past, three separate schemes traced customers' money in dormant bank, building society and NS&I accounts and outstanding premium bond prizes.
All three have seen a surge in inquiries since the government confirmed it was moving ahead with plans to take control of unused funds.
The Treasury defines unclaimed assets as those where there has been no "customer-initiated activity" for at least 15 years.
Under that definition, the industry estimates the amount of money lying dormant is approximately £250 - 350 million in bank accounts and up to £150 million in building societies. There is a further £466 million in dormant NS&I accounts.
Unclaimed money remains the property of the account holder or his next of kin.
The new website covers 42 banks, 59 building societies and all NS&I products, which should make it easier and quicker for consumers to be reunited with lost money.
"Mylostaccount.org.uk will enable account holders to initiate a search for their lost bank, building society and NS&I accounts at the click of a button," said British Bankers' Association (BBA) chief executive Angela Knight.
"It is a key part of the industry's commitment to make further steps towards reunifying customers with their money in advance of the statute-backed unclaimed assets scheme," she added.
"We want to reunite as many people as possible with their money; after all, it belongs to them," said Building Societies Association (BSA) head of savings policy Brian Morris.
"NS&I are very pleased to work with the BBA and BSA in reuniting savers with their lost money," said NS&I sales and customer retention director John Prout.
"We have all been leading the way for some time in helping people to reclaim lost or forgotten savings," he added.
The government has said that in future the proceeds of dormant bank and building society accounts will be reinvested by the government in a variety of community projects.
A central reclaim fund will set aside a proportion of money received to meet the cost of potential future claims - including accumulated interest - before the balance transfers to the Treasury.
The new fund will be independent of the government and the banks, and will be regulated by the Financial Services Authority. It is due to start in 2009.
The Treasury has been criticised for deciding not to include dormant money from NS&I accounts, and for proposing to make participation in the scheme voluntary.
Several other countries, including the Republic of Ireland, New Zealand, Switzerland and Australia, have introduced compulsory unclaimed assets schemes.