Change voicemail setting to max time possible

[Gabrio]

hi there,

i would like to change my voicemail settings so that the voicemail will kick in after the max time possible, so far it's about 25 seconds which is not ideal if you dont hear the phone or if you are driving. is it possible to have a longer delay at all?

thanks,
Gabrio

[Gabrio]

Samsung galaxy s8 - just tried with standard code and goes after 20 secs. I stopwatched with my watch.

[MI5 · Accepted solution]

@Gabrio the max is 30 seconds 

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

Your only other option is to turn off voicemail completely by dialling 1760.

[Gabrio]

Thanks but still 20 sec0nds.. does it take a while to update?

[MI5]

No, not usually but the phone does receive the call before it starts ringing.