At certain stores shoppers can click on a chip and pin machine or use a donate button online to round up purchases to the nearest pound and have the extra cash handed to charity.
It's a painless way to donate and seems to work: the electronic charity box has raised £1m from 4 million donations of an average 25p a time through Domino's Pizza, Screwfix, The Entertainer and others.
There are still only a limited number of businesses signed up for the deal. The more that do so, the more cash will be raised.
Many people who want to give to good causes have had to cut back in the recession. Pennies offers a way to help without risking going into the red.