Many NHS patients could soon be able to make an appointment to see their GP over the internet.
Practices will decide whether to offer the service
Leeds-based firm EMIS provides computer software to 55% of GPs in England. It has developed a programme that allows patients to make appointments online.
The software has been successfully tested by 150 practices and is now being made available to EMIS customers across the country.
The company says it could help the NHS to save millions of pounds each year.
The programme, called EMIS Access, allows patients to view GPs' timetables online and book or cancel appointments 24 hours a day.
It also allows patients to send confidential queries to their GP and to update their own contact details over the internet.
Patients can access the online booking system through the practice website or through the Patient UK website.
Staff at Dukes Avenue Practice in Muswell Hill in London say around one in 10 of its patients use the system.
"The bulk of our patients are professional people who are very computer literate," said practice manager Lesley Mayo. "For them, having access to an online booking facility is ideal."
Marple Cottage Surgery in Stockport said 15% of its patients are using online booking. They say it has also helped to free up staff.
"With little involvement needed from reception staff, it has freed them to concentrate on developing other areas of our service," said practice manager John Taylor.
It is up to individual practices to decide whether or not they want to make the service available to practices.
But Sean Riddell, deputy managing director of EMIS, is confident that many will.
"We are expecting wide-spread take up from our GP customers."
Dr Paul Cundy of the British Medical Association backed the service.
"I think it's an excellent development," he told BBC News Online.
However, he warned it would probably only benefit certain groups of patients.
"We know that many socio-economic groups and age groups do not use computers.
"This should not be seen as the way forward, but rather as a way of increasing the facilities available to patients."