Two private companies have joined forces to produce a list of the UK's 250,000 wealthiest people so charity fundraisers can target high net worth individuals.
The database, which is known as MID-AS, has been launched by Matrix-Data, a company specialising in wealth information, and fundraising research experts Prospecting for Gold.
Charities will be able to pay for various services, including cross-referencing their donor lists with MID-AS data to identify particularly wealthy people, or finding millionaires within a specific postcode range.
The data analysts are also able to provide 'deep profiling' on key donors to indicate their spending potential. Howard Jenkinson, a director at Matrix-Data, said: "This could include where they live, whether they are donors or trustees, who they know, who they work for, who they network with and whom they influence."
Data has been gathered from the media, share registers, public records of large stock transactions and corporate mergers and acquisitions. "We identify millionaires who are already charity donors," Jenkinson explained.
"Charities might prefer to suppress these people from general mailing lists, because if you ask for only £20, that's all you get."
Lindsay Boswell, chief executive of the Institute of Fundraising, said: "There are few charity organisations that don't have donors on their databases who are giving small amounts but could give more if a proper relationship was built up." He added that MID-AS would be "incredibly useful".
However, Graham Leigh, director of Development at the Directory for Social Change, said wealthy people should come forward of their own accord. "It is time rich people were proactive in finding causes they care about, and more generous and outspoken about charities they support," he said.