Non-geographic numbers; What they are and the types of NGNs
Believe it or not, but Non-geographic numbers or NGN’s make up the biggest group of numbers on the UK Numbering Plan. This also means that most number prefixes in the UK are difficult to contact from abroad, but that’s a problem that no longer needs to get you down. Below we have summed up what exactly Non-geographic numbers are, who uses them, how calls are made and why they often can’t be called from overseas.