The UK National Health Service’s N3 broadband network has been upgraded to allow phone calls using Voice over IP (VOIP) technology.

The N3 network, provided by BT, is part of the NHS’s £12.4bn National Program for IT (NPfIT).

The upgrade – paid for by Connecting for Health, which runs NPfIT – means local NHS organisations will be able to converge their voice and data over a single network – a move that is expected to provide coast savings.

Voice enablement means two new services will be available to NHS organisations. An N3 Local Gateway Service that will allow them to connect their voice networks to N3 and make free calls to other network users.

The service will also offer nationally negotiated rates for fixed line to mobile calls – which currently account for 70% of NHS landline charges – through a partnership deal with mobile operator O2.

NHS hospitals, primary care trusts and other organisations will have to pay set up and rental fees which will vary depending on the existing local infrastructure.

Smaller NHS organisations, such as GP surgeries, will be able to use the N3 Hosted Voice Service, with BT hosting users’ IP telephony, managing the infrastructure and the billing process.

N3 is one of Europe’s largest virtual private networks with more than 20,000 connections across England. It is a key element of NPfIT, supporting other core parts of the program, such as the Choose and Book hospital appointments system, the care records system and electronic prescribing.

Earlier this year, BT won contracts totalling £36m from five NHS organisations to provide “community of interest” networks combining voice, data and video calls via N3.

The NHS in Cornwall has also tapped N3 to launch a £12.5m high-speed network linking hospitals, medical centers and GP surgeries across the county.