The Charities Buying Group, the sector bulk-buying enterprise set up by Leonard Cheshire, is forecast to make £2m in annual savings for its members.
Since its launch last year, the group has grown rapidly to encompass 334 charities with a total spending power of £600m.
The group is expected to make savings for the year worth £2m as a result of deals with its 102 suppliers. It is also estimated that the group will save £500,000 in electricity costs alone over its first five years of operation.
Michael Hodgetts, managing director of the Charities Buying Group, said: "We have been excited by the response from both charities and suppliers.
When we launched the scheme we hoped that through the provision of quality and cost-effective purchasing agreements we would be able to help charities become more cost-efficient. Our aim now is to raise awareness across the sector to give every charity the chance to benefit from the service we offer."
Members of the group include Action Aid, Age Concern England, the RNLI and Save the Children.
Among the suppliers that have signed deals with the group are Carphone Warehouse, Elf-Total, Argos, Mothercare and Toshiba.
Stationery, IT equipment, printing services, vehicles, electricity and gas, and travel and accommodation make up the main areas in which deals are struck. But more obscure goods, such as pressure-relieving mattresses, have been bought in bulk through the scheme too.
The group is still seeking more charities to join the scheme.