Lucy Swanson, the bank's head of community relations, explains that tax exemption and company support can boost staff contributions. She says: "We introduced Charity Plus so that staff donations would make even more difference to their chosen causes by adding on further contributions from the tax man and NatWest."
And Charity Plus is not just about regular contributions. Staff also have the option of being more flexible in their giving. Instead of the money regularly going to a chosen charity, it can accumulate in a special account, from which an employee can then donate, using a chequebook or charity card. Ms Swanson says: "Many like to respond to requests - which might include colleagues and relatives' fundraising efforts or one-off disaster appeals - using the charity card and chequebook."
But NatWest is not alone. It is one of about 5,000 UK businesses that run give-as-you-earn schemes.
M&G has a staff fund among its give-as-you-earn options. A staff charity committee decides where the money should go. Meeting at lunchtime or after work, the small group has raised pounds 120,000 since its inception in 1992.
At large organisations it is not uncommon to have a department dealing with community funding. Charlotte Hosie, of the accountants and consultants KPMG's Community Broking Service, says of her department: "We act as a go-between, matching KPMG's staff who are interested in giving support to the community with groups who need it."
The success of staff funds indicates how important it is that people feel able to fit donations to their own concerns. As Ms Swanson explains, such schemes put employees "in charge of their giving, rather than being pulled by whatever donation box is shaken in front of them".
More information about give-as-you-earn schemes is available at www.giveasyouearn.org or www.charitycard.org