iPhone Visual Voicemail

With O2 (as the original exclusive carriers for the iPhone back in 2007), the Visual Voicemail works.

I have been on a number of other networks and it appears not to be supported.

I am surprised that it is only O2 that supports this very useful feature.

Anyone aware of any other carriers who support it or, how to get your carrier to support it?

I am not keen on third party apps for this.

EE and Vodafone also support this feature

Ahhh, the dark side

I'm not sure what you mean

EE & Vodafone = The Dark Side

So if not O2, EE or Vodafone what carrier are you testing with? Are you talking about the smaller carriers that resell services of one of the full operators? If so, then less surprising they don't support visual voicemail (I know BT didn't when I was with them but that may have changed now they have bought EE).

I am using Three

Then I think they are the only one of the big operators that don't support it. A number of MVNOs won't but 3/4s of the big operators do.

It's a shame