Firstly you need pairing and connecting the first phone.
How to connect the second phones?
Step 1 Pair and connect 10BP with the first phone as above. Then turn off the Bluetooth of the first phone.
Step 2 Turn off the speakerphone(Press the hold MFB for 4s to power off).
Step 3 Press and hold MFB button for 7 seconds until the LED flashes Red and Blue alternately.
Activate the Bluetooth on your second phone and connect “Avantree 10B”. Now the second phone is paired and connected.
Step 4 Power off and on 10BP again. Then it will automatically connect with the last 2 paired phones.
Below is the Video Guide--Connect 10BP with two phones:
The default setting of 10BP’s multipoint function is on. If it can't pair two phones simultaneously, it may because you have turn off the multipoint function. Please follow the below instrument:
Press and hold the "V+" button 2 seconds to TURN OFF the Multipoint function.
Press and hold the "V-" button 2 seconds to TURN ON the Multipoint function.
(For Production ID below 15L2)