How do I make the Xperia device visible when using Bluetooth? (from Android 5.0 to Android 8.0)

Your Xperia™ device is visible to nearby devices as long as the Bluetooth® settings screen is open and the Bluetooth function is turned on. Once you leave the Bluetooth settings screen, your device is no longer visible.

Android™ 8.0

To turn on the Bluetooth function and make your device visible

1. Find and tap Settings > Device connection > Bluetooth.
2. Tap the on-off switch beside Bluetooth so that the Bluetooth function is turned on. 

Android 5.0, 5.1, 6.0, 7.0, 7.1 or 7.1.1

To turn on the Bluetooth function and make your device visible

1. From your Home screen, tap the Application screen icon.
2. Find and tap Settings > Bluetooth.
3. Tap the on-off switch beside Bluetooth so that the Bluetooth function is turned on.