The People's Operator offers competitive rates for calls, texts and mobile, but the key difference is that the firm will give 25% of its profits away to good causes through the TPO Foundation.
TPO consumers can also direct the firm to give 10% of their monthly spend (after VAT) on mobile services to a cause of their choosing, ranging from major charities to local groups.
"It's really as simple as that. Just by switching network and using your mobile phone as usual, you can make a difference," said the firm.
The People's Operator is launching today as a pay-as-you-go network, but intends to start pay-monthly deals and SIM-card-only options in early 2013.
Calls and texts are currently free between TPO users, but PAYG calls to other networks cost 12.5p per minute - around half the cost of the major UK operators - and texts are priced at 7.5p each. Mobile data costs 12.5p per Mb.
TPO's launch charity partners include the NSPCC, Dimbleby Cancer Care and Childline.
The company would not reveal which of the networks it is using, but The Next Web claims that it has agreed a deal with EE.
Andrew Rosenfeld (chairman), Mark Epstein (vice-chair) and Tom Gutteridge (vice-chair) founded The People's Operator and they are the sole shareholders.
Rosenfeld was chairman of the NSPCC Full Stop campaign, which raised around £250 million for vulnerable children in the UK.
In a statement on the TPO website, TPO chief executive Alex Franks said: "The People's Operator was started by a team of people who wanted to use everything they had learned at work to make a real difference in a completely new business model.
"We have brought in top talent from across multiple disciplines to build a great team. We hope TPO will make a huge difference to causes across the country and empower people and organisations to make their mobiles matter."