I get “you have dialled an incorrect number “ when calling 020 numbers

[Billduffers]

When calling 020 numbers I get the message you have dialled an incorrect number, but I have checked and these numbers are all entered correctly. 
one of the numbers even shows the identity of the company I am calling but still says it’s an incorrect number

help ?

[Carley_S]

Hi Billduffers

Welcome back to the community. 

Sorry to hear you're having issues with 020 numbers at this time. Can you confirm if this is happening on your landline or your mobile? 

[Billduffers]

This is my mobile 

[Carley_S]

Thank you for confirming this @Billduffers

Does the issue occur on WiFi calling or is it just calling normally? Does the same issue occur on these numbers if you are calling from a different location? Like when you call from home and from work. 

Are you able to contact the numbers at all from a different handset or landline to report this fault to them?