Quote:There is no *guarantee* that 0870, 0871, 0844 and 0845 (and similar) numbers can be terminated from overseas.
... as shown by Ofcom's view:
Ofcom is the national regulatory authority for communications in the UK.
Ofcom does not control access to UK services in other countries. Such access
is regulated by a combination of commercial arrangements (eg, for NTS,
non-geographic numbering) within a framework set by the International
Telecommunications Union (ITU) (eg, for geographic and mobile numbering).
Ofcom is aware that callers may experience difficulty in accessing UK
non-geographic numbers from outside the UK. This results from uncertainties
over financial returns for routing between international operators caused by
the variable cost of calls and imbalances between charges that can be
retained or passed on through international arbitrage. UK residents dialling
the non-geographic numbers of other countries from the UK frequently
experience the same or similar problems. Individual countries do not
normally permit access to non-geographic numbers from overseas. This is
because these services are differently priced from geographic services and
it is impossible for an operator in the originating country (which in many
cases may not be transmitting the international part of the call) to know
what the appropriate price and for the correct amount to be passed via
several carriers and be paid to the terminating operator.