Voicemail

[Jaycee24]

I need to change the time before voicemail starts. I’m using iPhone XR

[Enlli · Accepted solution]

Make sure WiFi is off and network type is 3G/2G then try this

https://community.o2.co.uk/t5/How-to-Guides/How-to-Lengthen-Ringtime-on-any-O2-Mobile/ba-p/1175217

[swatso3]

Hi, I've just spent an hour trying to do this and get a "Call forwarding connection problem or invalid MMI CODE (0)" error. Having read the posts i have tried it with wifi calling off , 4 G calling off, even with WiFi off completely. I can send an MMI to check the actual time (15seconds) but it will not accept a change request. Additionally I have turned off messaging and turned it back on again, then turned the phone off and on again and limited the phone to 3G. 

from the many messages on the subject it appears it works for the majority, but many others are unable to carry out this most basic function. Any help gratefully received