Contact Tracing: How to Opt In & Out on Android & iOS

This guide shows you how to control the Exposure Notifications (contact tracing) feature on both Android and iOS devices. You’ll learn how to turn it on when you want to help with public health efforts, and how to turn it off when you don’t. The steps are simple and take less than a minute once you know where to look.

What You’ll Need

Your Android phone (Android 6.0 or newer) or iPhone (iOS 13.7 or newer)
An active internet connection (to download or update the official regional health authority app, if you haven’t already)
Location services enabled on Android (required for the system-level tracing to work)
Bluetooth turned on (the system will usually prompt you, but it’s good to have it ready)

Step-by-Step

Opting In (Turning On)

Install the official app for your region. Search your app store for the COVID-19 or exposure notification app published by your local public health authority. This is the app that will actually use the system’s contact tracing. If you don’t have it, you can’t opt in at the system level.
Open the app and follow the onboarding. The app will ask for permission to use Exposure Notifications. Tap “Allow” or “Enable” when prompted. This is the core opt-in step.
On Android: After you allow it in the app, go to Settings > Google > COVID-19 Exposure Notifications (or Exposure Notifications on some phones). Make sure the toggle at the top is switched on. If it’s off, turn it on.
On iPhone: Go to Settings > Exposure Notifications. If you don’t see this menu, you haven’t installed a compatible app yet. Once the app is installed, the menu appears. Tap “Turn On Exposure Notifications” and confirm.
Check Bluetooth. Both systems will remind you to turn on Bluetooth. You can do this from the quick settings panel (Android) or Control Center (iOS). The tracing will not work without it.
Confirm your region. On both platforms, you’ll be asked to select your country or region. This is important because it links you to the correct public health server.
Verify it’s active. After setup, return to the settings menu. You should see a status like “Exposure Notifications are on” or a green indicator. On Android, you’ll also see a list of apps that have permission to use the system.

Opting Out (Turning Off)

Decide what you want to disable. You can either turn off the system-level tracing entirely, or just delete the app. Turning off the system setting stops all tracing, even if the app stays installed. Deleting the app also stops tracing but leaves the system setting on (which does nothing without an app).
On Android: Go to Settings > Google > COVID-19 Exposure Notifications. Tap the toggle to turn it off. You’ll get a confirmation pop-up—tap “Turn Off” to confirm.
On iPhone: Go to Settings > Exposure Notifications. Tap “Turn Off Exposure Notifications” and confirm. You can also just delete the health authority app from your home screen, which will also stop the system from collecting new keys.
Optional: Clear your tracing data. On both platforms, there’s an option to “Delete Exposure Log” or “Clear Tracing Data” within the same settings menu. This removes the random identifiers your phone has been broadcasting and the list of matches.
Verify it’s off. Go back to the settings menu. The status should now say “Exposure Notifications are off” or similar. On Android, the toggle will be grayed out.

Common Mistakes

Turning off Bluetooth instead of the tracing feature. If you just toggle Bluetooth off, the system still collects data but can’t exchange keys—this is not the same as opting out. You must use the dedicated Exposure Notifications settings.
Deleting the app but not the system setting. On iOS, if you delete the app, the system setting remains “on” but inactive. It’s not harmful, but it can be confusing. To fully opt out, turn off the system setting as well.
Assuming the system works without the regional app. The built-in Exposure Notifications system is just a framework. It does nothing on its own. You must have the official health app installed and have granted it permission.
Ignoring region selection. If you select the wrong region, your phone will not receive the correct keys from your local health authority, making the feature useless.

Tips

Keep your OS updated. Both Apple and Google have refined the tracing system over time. Updating your phone ensures you have the latest security and functionality.
Use the “Share Exposure Checks” option (iOS). If you want to help without constant tracing, some regions allow you to share your positive test result without turning on tracing. Check your app’s settings.
Understand the data. The system only stores random Bluetooth keys and dates. It does not collect your location, name, or contacts. Knowing this can make your opt-in decision easier.
Check your battery. Contact tracing uses a small amount of battery. If you notice drain, it’s usually not the tracing—it’s more likely the Bluetooth radio. You can still keep tracing on and just disable other Bluetooth devices.

Troubleshooting

The “Exposure Notifications” menu doesn’t appear on iPhone. This happens when no compatible app is installed. Download your regional health app from the App Store, then the menu will appear.
On Android, the toggle is grayed out. This usually means your phone’s manufacturer or carrier has disabled it, or your Android version is too old. Check for system updates, and if it’s still grayed out, contact your carrier or phone maker.
You opted in but the app says “tracing unavailable.” Make sure Bluetooth is on and location services are enabled (Android requires this for scanning). Also, check that your date and time are set to automatic—incorrect time can break the key exchange.
You opted out but still get notifications from the app. That’s the app’s own alerts, not the system tracing. You can turn off notifications for that app in your phone’s app settings.
You want to re-enable but can’t find the setting. On iOS, go back to Settings > Exposure Notifications. On Android, go to Settings > Google > COVID-19 Exposure Notifications. If it’s missing, reinstall the health app and go through the onboarding again.

Frequently Asked Questions

Does contact tracing track my location?

No. The system uses Bluetooth to exchange random IDs with nearby phones. It does not use GPS, Wi-Fi, or your IP address. Your location is never recorded or transmitted.

Will my personal data be shared with the government?

Only your random Bluetooth keys and, if you test positive, your diagnosis are shared with the public health server. Your name, phone number, and contacts are not part of the system. The app itself may ask for additional info, but that’s separate from the tracing system.

Can I opt out after I’ve already opted in?

Yes, at any time. Just follow the steps above to turn it off. You can also delete your tracing logs, and the system will stop collecting new keys immediately.

If I delete the app, does that automatically opt me out?

On iOS, deleting the app stops all tracing, but the system setting remains “on” in Settings. On Android, deleting the app also stops tracing, but the system toggle stays on. To fully opt out, turn off the system setting as well.

Does contact tracing work across Android and iPhone?

Yes. Apple and Google built a joint system that works across both platforms. Your phone exchanges keys with any other phone that has the feature enabled, regardless of brand.

How long does the phone keep the tracing data?

Random IDs are stored for 14 days, then automatically deleted. The list of matches is also kept for 14 days. You can manually clear it anytime in the settings menu.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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