The structure for allocation of subscriber digits to indicate a provider is intrinsically wasteful (the provider necessarily is allocated a standard block size regardless of the number of customers) and can limit the number of providers to which numbers may be allocated. The current arrangement for example does not enable another operator to enter this market as the digit space is full unless the introduction is on the basis that the new operator accept a two digit prefix that has a first digit that is already well known to consumers as being ‘owned’ by a separate provider.