The amount raised by the Pennies microdonation scheme has doubled in the last six months to reach £500,000.
Pennies has also reached the two million individual donations milestone in half the time it took to reach the first million.
Last November, a year after its inception, the charity reached the one million donation mark and had raised £250,000.
Individuals paying by credit or debit card at participating retailers can chose to round up their payment to make a donation. The majority of the donation goes towards the retailers chosen charity or charities and the rest is divided between charities chosen by Pennies.
So far 29 charities are benefiting and ten national retailers have signed up alongside a number of smaller sellers.
Alison Hutchinson, chief executive of the Pennies Foundation said: “We have been delighted to see the public embracing micro-donations and joining the Pennies movement.”
The charity to benefit the most from the scheme so far is the Special Olympics GB through Pennies' Domino's partnership. It has received over £185,000 through the scheme. Chief executive of the charity Karen Wallin said she believed that "Pennies is a giving revolution" and urged other retailers to get on board.