The National Fundraising File contains profiles of 318,314 people who have donated to more than one charity. Eighty-six per cent of those profiled have given to up to four charities at the same time.
The file, compiled by data list company EDM Media, lists retired homeowners aged 60 or over who have made an average cash gift of £10 to a range of charitable causes, including medical research, animal welfare, children and international aid organisations.
Its creators, who pooled 15 charities' lists to create the file, claimed all those listed are receptive to mailings, particularly to appeals and sweepstakes.
Lisa Neville, operations director at EDM, said the file was designed for smaller organisations seeking to buy selected lists of names as well as for new charities with no data of their own.