There has been much written about "UK scammers" using 070 (+4470) numbers to scam people. Some of the stuff written here is true and some of it is plain myth. So, I will attempt to put the record straight.
What is an 070 number?
It is a "follow me" number. It does not go directly to a specific telephone, but it IS used primarily by legitimate users. Unfortunately, also the scammers from Nigeria and the like have also latched onto the way these numbers work and found them useful.
I used to use one of these numbers myself when mobile coverage was not as good as today, but now I never use it. In fact I would have to look up the number to remember it! These days mobile coverage in the UK is good enough for me to just rely solely on my mobile.
How it works:-
Many of these numbers are given away "free" to the user as they attract a premium call rate. Instead of being charged at a standard mobile rate to an 07xx number, there is a higher charge for calling a number starting 070. This effectively funds the number provision and the more calls made to that number, the more the provider makes from its use.
So, say I have an 070 number. What can I do with it?
Well, it allows me to divert calls to that number to any number I like based upon the time of the call, so I can use it to "follow me" wherever I go and I can change those profiles on the fly by either dialing a control number linked to it, or via the internet management system.
If I use it for business I could use it to filter my calls. For example, I can have it divert to my mobile in business hours so that sales calls always get through to me during the working day and divert to a voicemail service "out of hours" so that my leisure time is undisturbed. If I have a home based business but still want to preserve my leisure time, then I could have it call my home landline during the hours I want to work and divert to voicemail outside those hours.
If I use it for leisure then I could give it to my friends and make it call my business desk phone between 9am and 5pm, my mobile between 8am-9am and 5pm and 6pm whilst I am travelling and to my home number after 6pm, then after 11pm divert to voicemail.
All in all, it is a very useful service for people who want to manage their availability for being contacted.
However, scammers use these numbers too and there are some providers who will allow diversion to foreign numbers at minimal cost. As a result, you could call one of these numbers and actually be speaking to someone in any country in the world! This is why it is best to be wary of them.
If you are asked to contact someone on one of these numbers, then be wary. If the person is legitimate, then if asked they should have no problem with giving you an alternative genuine UK mobile or landline number for you to call. These days thanks to the excellent mobile coverage we have here in the UK there are an increasing number of people who simply don't have a landline. They don't need one as they can rely on their mobile.
Genuine UK Landline and Mobile (Cellphone) Numbers
Genuine mobile numbers are 074xx, 075xx, 076xx, 077xx, 078xx, and 079xx (+4474, +4475 +4476, +4477, +4478 or +4479 from outside the UK). Genuine landline numbers will begin 01, 02 or 03 (+441, +442 or +443 from outside the UK).
I hope the above helps people decide who to trust and who to be wary of.