The scheme, which will be launched in February, is similar to one started by the charity Pennies last week, which enables customers of the pizza chain Domino's to make donations to charity by rounding up their bills to the nearest pound.
Sophie High, senior project leader for Give Change Make Change, who is also in the CRUK innovation team, said the scheme was originally devised by CRUK, but it decided to approach the other charities because it saw the scheme as an opportunity for the whole sector.
The first partner to come on board for the scheme is The Hut Group, which owns many online brands, including zavvi.com.
High said retailers would be able to add other charities to the group that would receive donations. An administration fee of 0.85p on each transaction will be charged by the technology supplier, with the rest going to the charities.
She said she hoped the scheme would prompt a new type of consumer behaviour: "I want it to become standard for people to round up their purchases for charity."
High added that there were plans to take the scheme offline eventually. She said: "It works across all consumer transaction types."