Increase ringing time before going to voicemail

[Koala]

I have seen several posts on this but nothing that ever provides a solution. My ringing time before going through to voicemail is about 17 seconds and I want to increase this.

I have tried the code to try and increase the time as I have the newer SIM,  **61*+447458333222*11*30#  but I get an error message as other users appear to have done. It states:

Call forwarding
When no reply for All Speech Services
Connection problem or invalid MMI code

When I try *#61#  to see what it is set to but it states 'not forwarded' to all items listed.

Voicemail is working fine, and the calls do go through to voicemail after the 17 seconds. Please can anyone advise how I can increase the time as it is very frustrating? 

[enlli]

Actually thinking about it the 121 is wrong

**61*222*11*30#, may do it

I found that it seems to be a problem with Samsung. My S20+ would not change the ringtone on Vodafone. I got the comma bit from a Samsung user group and it worked 

[Koala]

Unfortunately I get the same error message, with and without the comma. I tried putting my sim in to an older phone (unfortunately also a Samsung) but I get the same error messages. 

[ColinTaylor]

Hi Koala,

Did you ever solve this? I'm having exactly the same problem with my Samsung A50, invalid MMI code. The dialled numbers work on my Samsung S6 but not on the A50.

Colin