is there a way to dial straight to voicemail on uk mobiles?

[spann0]

I need to get straight to someones voicemail even if they are picking up how do u do that?

[daveydude]

I need to get straight to someones voicemail even if they are picking up how do u do that?

Text them first and tell them not to answer?

[spann0]

Text them first and tell them not to answer?
nah they can't know i called

[Geezer]

I used to be able to do it but then the company sussed it and stopped if so I'm not sure if it's still possible.