The UK’s National Health Service (NHS) is trialling a medical chatbot as an alternative to its non-emergency helpline. The app, made by UK startup Babylon, asks people questions about their illnesses in a chat window before giving them advice — whether they should go to a doctor, or if the problem is likely to pass in time. According to a report from the Financial Times, the app will be used from the end of January for six months in locations across London, and will cover more than 1.2 million residents.

The NHS’ non-emergency helpline, 111, is different to the emergency service and not staffed by medical professionals. Each call to 111 costs the NHS up to $20 and takes approximately 10 minutes to complete. The service has previously been criticized by the UK’s national health watchdog, the Care Quality Commission, with a report stating that calls to the service were too frequently abandoned, or callers given inappropriate advice.

Babylon hopes it can remedy this situation, with its artificial intelligence-powered chatbot handling basic enquires — triage, not medical diagnosis. Conversations handled by the app take a minute and a half on average and last for 12 back-and-forth exchanges. Babylon chief executive Ali Parsa told the FT that the commercial agreement between the NHS and the company would offer “substantial” cost savings, but would not give any financial specifics of the deal.

It’s not the first partnership Babylon has established with the NHS, which has previously tapped the startup for its administrative skills. In Essex, Babylon is currently offering video consultations with doctors via its app to a population of around 21,500. The company says 20 percent of patients at one surgery have used the app, and that the service has reduced local visits to both A&E and walk-in centers. Such video consultations are also available to individuals outside this catchment area at cost — £25 ($30) for a one-off appointment or £5 ($6) for a monthly subscription.

Babylon is just one of a number of medical chatbots around the world, and in China, search giant Baidu has launched its own, named Melody. And in the UK, the NHS is experimenting with other digital services. Google’s AI division DeepMind has signed a number of deals with the national health provider, including one to create an app that alerts doctors about patients’ potentially dangerous medical conditions.