Up to three million people in Africa and other parts of the developing world will get access to their own mobile phone number under a UN-backed scheme to reach people living on less than $2 (£1.20) a day.
Cheap mobile phones have revolutionised lives in poorer countries, helping link farmers to markets, enabling people to send payments and helping them look for a job.
But a third of mobile users in some African markets have to borrow phones to make calls and often have to pay a "borrowers' premium". The plan aims to give these people a low-cost option to acquire their own "mobile identity" that can be accessed from any handset.
"There are a lot of people who share or borrow phones," said Ramona Liberoff of the British technology provider Movirtu. "We give shared phone users their own mobile identity, opening up the world of mobile banking and payments."
The main target for the scheme, backed by the UN Development Programme, is to get a mobile number to 2.4 million more women. In rural areas in much of the developing world, women are far less likely than men to have their own phone.
The "cloud phone" technology is being piloted in Madagascar, where people can sign up for their own number, receive a PIN and the ability to purchase airtime. They can then log in and use their number from any handset.