Hi - i had no problems in pairing. Turn ST3 off. Press and hold the green ON button for about 4/6 seconds till you hear 'For British English...' - when you hear the language you want, press the green button again. You will next hear 'turn your phones bluetooth on..' or something along those lines. Make sure BT is switched on you iPhone, and you should see the ST listed as a found device on the iPhone - select it and when prompted enter 0000 (four zeros) and NO # symbol - just the numbers - click OK/Done/Pair (whatever the button is) and it should synch up at that point.