Bluetooth tracing

Bluetooth tracing allows you to create an anonymous record of the people you’ve been near. It is easy to use – you only need to turn it on once.

Last updated: 27 June 2022

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How Bluetooth tracing works

Bluetooth tracing lets your phone exchange anonymous random keys with other nearby phones that also have Bluetooth tracing enabled. You don’t have to have the app open for it to work.

If you or another app user in your community tests positive for COVID-19, a Bluetooth alert can be sent to quickly notify any other app users who have been in close contact.

This helps us keep our communities safe without compromising anyone’s privacy.


[Animation showing someone scanning a QR code]

You already know about scanning QR codes with the nz covered tracer app, now the app has an additional new feature called bluetooth tracing.

[Animation showing two people sitting nearby in a cafe. Their phones give each other a digital high five]

It's basically your phone giving an anonymous digital high five to nearby phones who are using the app.

It doesn't know whose phone it is or even where you were meaning your privacy is always protected.

[Animation showing two phones with bluetooth tracing detecting how close they are from one another and for how long]

All the bluetooth tracing function knows is how close the other phone was and for how long.

[Animation showing someone enabling Bluetooth tracing in the app]

Download the latest version of the app and you'll get the option to turn the bluetooth feature on.

[Animation showing phone sending out secure random ID codes]

Your phone will then start sending out private secure random ID codes even when you're not using the app. This is automatic and won't use much battery or any data.

Then when someone tests positive for COVID-19 they can send out an anonymous alert containing all the random IDs they have broadcast over the past 14 days.

[Animation showing a phone sending out an anonymous alert to several phones]

Anyone whose phone has collected one of these IDs will receive an alert and advice on next steps to stay safe.

No information is exchanged about where they were or who they are.

So keep scanning those QR codes Wherever you see them and turn on bluetooth tracing so you can be alerted quickly if you've been exposed to the virus.

Protect your whanau and the community turn on bluetooth tracing.

Turn on Bluetooth tracing

Bluetooth tracing is optional but strongly recommended. The more people who use it, the more effective it will be.

Bluetooth tracing is disabled by default. However, the first time you open NZ COVID Tracer after installing the app or updating it to version 3.0.0 or later, you’ll be prompted to enable Bluetooth tracing. 

Watch this video to learn how to turn on Bluetooth tracing or check whether it is already on, or follow these steps (you’ll need to be connected to the internet when you first enable Bluetooth):

  • Open the app (v.3.0.0 and later) and tap on ‘Dashboard’ if it isn't already open.
  • If Bluetooth tracing is enabled, the 'Dashboard' will state that “Bluetooth tracing is on”. Otherwise, it will state that “Bluetooth tracing is off”.
  • Tap on the ‘Bluetooth tracing is off’ tile to bring up the option to ‘Turn it on’.

Screenshot showing Bluetooth switched off

Continue to scan QR codes

It’s important you continue scanning the QR codes wherever you see them, regardless of whether you also have Bluetooth tracing enabled.

The QR codes help you keep a private record of the places you’ve been, while Bluetooth tracing allows you to keep an anonymised record of the people you’ve been near. 

Bluetooth alerts

You may receive a Bluetooth alert if you were near a person with COVID-19 who has been using Bluetooth tracing and if you also scanned the QR code at a location visited by that person.

More information on NZ COVID Tracer alerts and what to do if you get an alert.

Send a Bluetooth alert

If you use Bluetooth the contact tracer will ask if you want to send a Bluetooth alert. If you agree they will provide you with a verification code. To initiate the alert:

  1. Open the NZ Covid Tracer app.
  2. Go to the My data screen.
  3. Tap on Share my Bluetooth tracing codes.
  4. Enter the verification code given to you by the contact tracer.

This will send a Bluetooth alert to the other app users who have come near enough to you for long enough to be at risk of exposure.

Sending a Bluetooth alert does not: 

  • upload information about where you have been or who you have been close to
  • identify you. 

It will only alert the people who have been near you that they may have been exposed and need to be tested.

Facts about Bluetooth tracing

Your personal data remains private

Bluetooth tracing is entirely anonymous. No personal or identifying information is exchanged between phones, and Bluetooth tracing cannot be used to track your movements.

This means no one will ever see who you’ve been nearby, or when or where you were near them, even if you test positive for COVID-19.

Read more about how privacy is protected in the NZ COVID Tracer app.

Bluetooth tracing doesn’t use mobile data

Bluetooth doesn’t use any mobile data because it doesn’t involve connecting to the cell phone network – your phone talks directly to other nearby phones.

Minimal impact on battery life

Bluetooth tracing uses Bluetooth Low Energy (BLE), which is designed to use considerably less power than Classic Bluetooth. As a result, the impact on phone battery life will be minimal.

Uses features developed by Apple and Google to help contact tracing

Bluetooth tracing uses a feature called the Exposure Notification Framework that is built into later versions of the iOS and Android operating systems. The ENF is a simple algorithm that has been developed and published by Apple and Google specifically to improve digital contact tracing efforts around the world.

Read more about the Exposure Notification Framework

Which devices can use Bluetooth tracing

To enable Bluetooth tracing, your phone will need:

  • iOS 12.5 or higher for iPhones
  • Android 6.0 or higher for other phones, plus support for Bluetooth Low Energy and Google Play Services

Phones with older operating systems cannot provide Bluetooth tracing because they do not have the Apple/Google Exposure Notification Framework.

If you have an iPhone with iOS 10 or later you can still use the NZ COVID Tracer app to scan the QR codes and add manual entries to your digital diary, and you will still receive location alerts if you have them enabled.

Your phone will display this image if it does not support Bluetooth tracing.

Screenshot showing a device that doesn't support Bluetooth tracing


If you believe your smartphone supports Bluetooth tracing but you are having trouble getting started:

  • Check that you are connected to the internet when you try to enable Bluetooth tracing for the first time. You don’t need to be connected to use Bluetooth tracing, but there is an online check that happens the first time it runs.
  • Check that your operating system is up-to-date. Unfortunately, some phones can’t update to the latest version of iOS or Android, but many of them can.
  • It can take several minutes for Android phones to check whether they're compatible with Bluetooth tracing. Please be patient and try restarting your phone if the ‘Checking exposure keys’ message doesn't disappear within around 10 minutes. Do not uninstall or reinstall the app, as this will delete your digital diary.

Try the steps below:

For iPhone

  • Go to your phone settings and find the NZ COVID Tracer App Icon. Select Exposure Notifications. Then select the “Set As Active Region”.
  • It will then grey out and you will be able to activate Bluetooth tracing.

For Android

  • Go to your phone’s settings and find Google Services and Preferences. Select Exposure Notifications. Turn ON.
  • Then enable Bluetooth tracing on the dashboard of the app.

Read more about using the Exposure Notifications System on Android phones

Read more about why some Huawei phones do not support Google Play Services

Please also see questions and answers on the NZ COVID Tracer app.

If your phone doesn’t support Bluetooth tracing

If your phone doesn’t support Bluetooth tracing, you can help keep the community safe by keeping track of where you’ve been and who you’ve seen in other ways:

  • If you have a smartphone running at least iOS 10 or Android 6, you can use the NZ COVID Tracer app to scan the QR codes, keep a digital diary, and get location notifications if you visit a location at around the same time as someone who has COVID-19. 
  • If you have a smartphone running at least Android 5, you can use the Rippl app to scan codes, keep a digital diary, and get location notifications.

If you think Bluetooth tracing is affecting your battery usage

If you think your battery usage is excessive, please contact our support team so we can look into the problem. You will need the following information:

  • Percentage of battery used (refer to phone settings)
  • The make and model of your phone
  • Your phone’s version of iOS or Android

If your phone is getting hot

Bluetooth tracing will not cause your phone to overheat because it uses Bluetooth Low Energy (BLE), which is designed to use considerably less power than Classic Bluetooth.

However, please note that having a large number of active apps open at the same time could cause your phone to overheat by placing excessive demands on your phone’s hardware.

If you’re on Android 10 or older

On Android 10 and older, the Exposure Notification System (ENS) requires the Location setting to be active. Bluetooth tracing relies on the ENS in order to function. The ENS does not require the Location setting to be active if your phone is running Android 11 or later.

Please note that NZ COVID Tracer cannot access your GPS location or any other data about your phone’s location.

Read more about location permissions and the Exposure Notification System on the Google website.

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