simonclark123@hotmail.com presented the following explanation :
> On 23 May, 11:29, bo...@hotmail.com wrote:
>> On Fri, 23 May 2008 08:49:16 +0100, "JT" <justinthym...@hotmail.com>
>> wrote:
>>
>>> How is a ported number recognised by a caller's network for charging
>>> purposes? *As the new network or as the original?
>>
>> As a part of the network that currently owns the number.
>>
>> Borje, from Sweden
>
> It's not as simple as that in the UK.
>
> If the caller is calling from a landline, then they will be charged as
> per the *original* network.

Correct.

> If the caller is calling from a mobile, then they will be charged as
> per the new network

Are you sure? I was always under the impression that they either treat
it as on-net or off-net.

> (calling from o2 PAYG used to be an exception to
> this, but probably not any more? Steve Terry will probably know the
> answer to this!).
>