Beware when buying a number from one that is advertised with the whole number as these can be stolen as was the case with me recently. I bought 07500 369 369 that came with a sealed O2 package showing the correct number but when I tried to register the Sim the number was not available. O2 customer services said it was already registered to someone on the Orange network and as yet no explanation why or how this is possible.
I received another number from the seller "who has a great feedback" but still no explanation why or how this happened, it leaves me thinking was this number stolen or had it already been sold to someone else. I know if I was the seller I would be finding out before I sold any more and be seeking to get the original number returned to it's rightful owner
The way to stop this, is the seller should also supply the PAC code along with the number