Phone rings but doesn't go to voicemail

[Sunshine45]

Hi

I have just got a new sim from 02 for an existing contract I've got so that I can take it out of an old Samsung (not smart) phone to put in an iphone 6. It works ok in that you can call it and it rings, receives and sends texts etc BUT the phone doesn't go to voicemail - ever. I use this for business and need it to go to voicemail so I don't miss calls form customers. You can dial 901 and access the voicemail but it's as if the phone isn't forwarding to it. Call forwarding is off. Cellular data is on. Any ideas please?

[jonsie · Accepted solution]

Dial 1750 to turn on voicemail

Guide: All you need to know about O2 Voicemail 901 

[jonsie]

Also you can adjust the number of rings before going to voicemail

Guide:How to Lengthen Ringtime on any O2 Mobile