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Laurie Clarke


How will the NHS Covid-19 contact tracing app work and when will it go live?

This article is regularly updated to reflect emerging developments. 

Back in May, the NHS announced the imminent launch of a coronavirus tracking app that would let users know if they’ve been in close proximity to someone infected with coronavirus and need to self-isolate. 

However, a series of missteps led to the app in its first iteration being dropped and the government saying it would pivot to the model being developed by Google and Apple instead on June 18.

Read next: Where did it all go wrong for the UK’s Covid-19 contact tracing app?

The original app was piloted on the Isle of Wight, where it became clear that technical issues with the centralised app design meant that it wasn’t functioning properly on iPhones.

The app was initially considered to be one of the central planks of the government’s strategy for how the UK could gradually lift lockdown conditions, but is now considered to be an add-on to the wider Test and Trace programme. 

On June 17, a government minister said that the UK’s app wouldn’t be ready until winter, but other government officials have failed to commit to any date at all. At the moment, it’s not clear when or even if the app will launch.

How will the contact tracing app work?

The app will log, using Bluetooth LE (a standard feature that runs continuously and automatically on your smartphone), the proximity of other people who have the app installed. A record of this “anonymous proximity information” will be stored on the device. Users will be encouraged to enter into the app whether they have experienced symptoms of coronavirus. If a user reports symptoms of Covid-19, all of their contact data for the previous 28 days will be uploaded to the central server. All of the people they came into close contact with will then receive an alerts of the need to self-isolate.

If someone reports symptoms, a contact tracer will get in touch and, depending on their responses, may arrange for them to take a Covid-19 test.

When will it launch?

There is no firm launch date for the app as of yet.

Will it be voluntary?

The app will be voluntary to download. However, according to researchers, it will only be effective at tracking and curbing the spread of coronavirus if at least 56 to 60 per cent of the population download it. The adoption rates of other nations’ coronavirus tracking apps are not particularly hopeful. Only one in six people signed up for Singapore’s voluntary TraceTogether app. 

Will it infringe on my privacy?

When the government planned to launch a centralised app, there was concern over whether users’ data would be safe. A number of privacy experts highlighted a range of problems associated with the planned design, including that the data can be used to build a social graph of an individual’s contacts, that this type of app is vulnerable to mission creep, and that individual’s could theoretically be subject to persistent tracking using the app. 

Wariness around that app was fuelled by a report from the Guardian revealing that a draft government memo explaining how the NHS contact tracing app could work noted that ministers might be given the ability to order “de-anonymisation” at some point to identify people from their smartphones. It said the app could use device IDs, which are unique to all smartphones, to reveal users’ identities, if deemed “proportionate at some stage”. It didn’t detail under what circumstances such a measure would be ‘proportionate’. A spokesperson from NHSX denied that this had ever been on the table. 

However, the Apple and Google framework is decentralised, meaning data is stored on the phone instead of being sent to a central database. This, privacy advocates argue, means that this model is far less intrusive and prone to being exploited.