Sometimes that's because a lot of the call routing logic and even queuing is done at the network level (the 0845 layer) before the call is delivered to the final delivery numbers (i.e. the 'real' number). The number of physical lines behind a 'real' number might be limited and they could all be busy or even defunct. For instance one single 0845 number (e.g. HMRC) could route to 50 real numbers in 5 call centres.

Saynoto0870 et al are great but the best solution would be for Ofcom to force providers to include calls to 08** numbers in your bundled minutes.
( custardthehedgehog, Thu 29 Sep 2011, 10:05, Reply)