The Big Give has extended the application deadline for its Christmas Challenge match-funding campaign until Friday 19 July.
The campaign allows charities to apply for up to £25,000 in funding if they have other donors prepared to match-fund the money.
It opened on 20 May and was originally expected to close on 12 July, but the deadline has been extended by a week.
Any UK-registered charity with an income of more than £25,000 a year in its last annual accounts is eligible to apply.
Alex Day, director of the Big Give, said: "We are excited to have a bigger pot of match-funds this year, meaning that we can support even more charities."
Last year, he said, the Christmas Challenge had involved 589 charities and raised more than £13m.
"This year we are looking for charities working in a number of areas, including children, health, international development and the heritage sector," he said. "Some new champion funders are on board for the first time this year, including the National Lottery Heritage Fund."
For more information about the campaign, click here.