Prime Minister Gordon Brown has said that some of the money held in dormant accounts would be used to fund youth and community projects.
Up to £15bn could be held in dormant accounts
BBC News explains what dormant accounts are and how you can track down lost money.
What are dormant accounts?
The account passes from live to dormant when the bank or building society loses touch with the account holder for a period of three years.
Often the bank or building society will write to the account holder to tell them that their account is about to become dormant.
What happens when an account becomes dormant?
The account holder is barred from accessing their money in the standard way, such as through the post, branch or over the telephone.
Does that mean that account holders lose their money?
Absolutely not, they still legally own the money. It will continue to accrue interest - if any is payable - at the rate due on the account.
Tracking down dormant account useful contacts
British Bankers' Association 0207 216 8800
Building Societies Association 0207 437 0655
National Savings 0845 9645000
Unclaimed Assets Register 0870 2411713
However, banks and building societies have been accused of using the money held in dormant accounts to make their finance looks more healthy.
How can people access their money ?
They have to write to the bank or building society and ask for their account to be reactivated.
In order for any instructions to be followed, the account holder is likely to have to give some form of identification to prove who they are.
It is a little trickier when the account holder cannot remember the financial institution with which they hold their account.
However, the Building Societies Association (BSA), British Bankers Association (BBA), National Savings and Investments, and the unclaimed asset register all operate account tracing services.
What if the account holder has died?
A lot of dormant accounts are in the name of people who have died - many a long time ago.
When the estates of these people went through probate the administrators failed to trace the accounts.
In theory, descendants of the deceased may still have a right to this money.
However, in practice, the descendants are unlikely to be aware that it is exists and, anyway, proving their rights may be both difficult and time consuming.
What does the government want with the money?
There is an estimated £15bn held in dormant accounts.
Gordon Brown would like to see some of this cash mountain go to good causes - £15bn could have a huge impact on the plight of Britain's underprivileged.
However, the Conservatives have called for the money to be used to fund the pensions of workers who have lost their retirement savings following the closure of their company pension scheme.
Are more people claiming back their money?
It does seem the message that there is a huge pile of unclaimed money out there seems to be getting through.
The BSA has seen the number of people approaching them about dormant accounts increase ten fold between February and June this year.
In addition, the Halifax has said that it is actively seeking out customers with dormant accounts in order to reunite them with their money.