The Unclaimed Assets Charity Coalition is calling for UK charities to supply information that could help create a national register of dormant funds.
The coalition, which now has 43 charity members, was launched in June this year and opened its campaign with five key demands. One of these was that there should be a government-managed national register of unclaimed assets to ensure asset-holders could be reunited with their lost funds.
The register would also allow charities to track down lost holdings in order to claim a donor's legacy in full.
To achieve this, the coalition is asking charities to contact them with details of the number of comprehensive legacy records they hold and the number of new notifications they get each year.
Paul Farthing, legacy funding director at Cancer Research UK, said: "We know that public registers have already proved successful in other countries, such as the US and Australia, and are very keen to see a similar process adopted here."