The Big Give is offering to double donations made through its website to the Pakistan flood appeal.
Jon Brooks, managing director of the Big Give, which helps philanthropists find charities to support, said the organisation’s past success with similar funding initiatives encouraged it to launch this offer.
"We raised more than £100,000 in a week when we doubled donations for the Haiti appeal recently, and now we are keen to do the same for Pakistan," he said.
The Big Give has more than £70,000 available to double donations to six charities.
By the end of Friday, the Disasters Emergency Committee flood appeal had raised £12m.