How does the NHS Covid-19 Track and Trace app work?

The NHS Covid-19 app finally launched across England and Wales on September 24, after months of delays.

Health Secretary Matt Hancock revealed that the app had been downloaded more than 12 million times by midday on Monday.

He hailed it as ‘the fastest download of an app in British history’, and he told the House of Commons ‘I would urge everybody, including every single member in this House, to join the 12.4 million.’

But how does it all work?

What does the NHS Covid-19 app do?

According to the government’s website, the new app ‘enables anyone with a smartphone to engage with every aspect of the NHS Test and Trace service, from ordering a test through to accessing the right guidance and advice.’

You are encouraged to log any symptoms you may have into the app.

It also includes a feature that allows QR codes to be scanned for people to ‘check-in’ to public locations, such as pubs or restaurants.

Some 160,000 businesses have already downloaded QR codes for use in their facilities.

If you come into close proximity to someone who tests positive for coronavirus, you will receive a notification letting you know to self-isolate.

The app also tells people the level of coronavirus risk in their local area, by using postcode data that is provided when the app is first used.

The NHS app enables users to book a test, log their symptoms, and a countdown timer to keep track of how long to stay in self-isolation.

How does the NHS Covid-19 app work?

The app uses Bluetooth to tell how far away you are from someone else with the app.

If you are in close proximity to someone for more than 15 minutes, and they test positive for coronavirus, then you will be sent a notification letting you know to self-isolate.

You can also use the app to ‘check-in’ to venues.

If someone who tests positive for coronavirus was at the venue at the same time as you were, then you will also receive a notification telling you to self-isolate.

When will NHS Track and Trace app contact me?

The app will send you a notification the second someone you have come into close contact with someone has tested positive for coronavirus.

You will not be told who triggered the alert.

One of the main benefits of the app is that it is a great deal quicker than existing Track and Trace methods at alerting people to self-isolate.

If you are contacted because one of your contacts has tested positive, you must stay at home for 14 days from your last point of contact with them.

Even if the recipient has no symptoms or a subsequent negative test result, they must stay at home for the duration.

Failure to do so will land you with a fine up to £10,000.

What happens if I turn my Bluetooth or location off?

The app relies on you keeping your Bluetooth on, as it uses it to scan for potential exposures to people with the virus.

If you turn the Bluetooth off, the app will not work.

Many have concerns that the app may drain smartphone batteries.

But the app is likely to only drain 5% or less of your battery life, meaning you shouldn’t see a dramatic reduction in how long you can use your phone for.

The app does not request access to GPS features on your phone, so it is fine to turn it off.

Why do I have to check-in to venues with a QR code?

It is important to check in to a venue, even if your Bluetooth is on, as you are at a higher risk of contracting the virus than if you are outside.

People tend to stay in venues for more than an hour, they move around to go to the toilet, they touch surfaces, and a waiter could be carrying germs.

Checking in to a venue gives you, and other customers, a better chance of being told when to self-isolate before it is too late.

Is it compulsory to download the app?

Downloading the NHS contact tracing app is not compulsory, however, it is recommended.

The more people have the app downloaded and active on their phones, the better it works.

A recent study by a data team at Oxford University, looking at the experience of Washington State in the US, found that if 15% used an app that notified them of exposure to an infected person, infections were reduced by 8% and deaths by 6%.

The NHS had aimed for 80% of smartphone users to download the app or about 56% of the population.

Although 12.4 million people sounds like a lot, it is actually only 5.4% of the population of England and Wales.

How do I download the app?

You can download the app straight onto you smartphone from Android’s Google Play or Apple’s App Store – but not on tablets, smartwatches or other devices.

Your phone must have Android 6.0 or iOS 13.5 and Bluetooth 4.0 or higher.

That excludes the iPhone 6 and older versions of Apple’s handsets.

Some more recent Huawei phones will not load the app either.

The app is  available to people aged 16 and upwards, and currently available in eight languages, including: English, Welsh, Bengali, Urdu, Gujarati, Punjabi, Chinese, Romanian, Turkish and Arabic.

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