Charities that run projects to help older people will be the first to benefit from the Balance Charitable Foundation, which opens for applications tomorrow.
The foundation was launched a year ago to give unclaimed money in dormant bank accounts to charities. It will issue minimum grants of £50,000 at the end of this year from the first stream of applications.
Two further rounds in 2006 will also benefit projects helping disadvantaged and vulnerable older people, particularly those over the age of 75.
Deputy chairman Michael Webber said current funding was "very substantial".
He said the eventual fund is likely to reach a "ten-figure sum", a figure substantiated by estimates that around £20bn is held in dormant accounts.
"Three financial institutions have received Financial Standards Authority approval to free up funds," he said. "But the expected timing of their receipt is unclear, so we can't give a firm figure as to how many grants we will make."
Webber said grants would be delivered on a long-term basis of up to five years.
However, the figure could decline following recent reports (Third Sector, 23 March) that the Treasury is considering letting banks divert funds into their own charitable arms.