A Radio 5 Live investigation suggests that enough money is collected to give a home to every homeless person.
Last year charities set up to help the homeless in London raised more than £100m. They say that 20,000 people live in hostels or on the streets. According to their own figures that is enough to pay the mortgage on a £60,000 house for each homeless person in the capital.
In total, 116 charities run more than 500 projects. They employ 3,000 staff.