Wait... your cell phones adhere to a different numbering scheme than your land lines? How does THAT work?
We have particular "area codes" for cell phones, all starting 07. All costs are covered by the dialer (incoming calls are free in all cases) and the cost of calling a cell phone is higher than a land line (in many cases by more than an order of magnitude) so it is important that the caller knows it is a cell phone.
We have a few different ranges, 01 and 02 are specific geographical areas that are charged normally, 08 is generally cheap or free non-geographical and 09 are generally very expensive (sex lines and such).