O2 also allow calls to 0844 in there inclusive minutes,which opens up a few more cheap call options.Orange still allow access to 0800 on contract phones.
Even though other suppliers dont offer calls to Ngn no,s in there packages you can use them to reduce your bill.(PROVIDING YOU CHECK WITH YOUR NETWORK WHAT THEY CHARGE TO CALL EACH NGN CODE).
Lets take Virgin Payg as an example they charge to call
0845. 10p a minute.
0844,0870,0871. 15p aminute
Normally it would cost you 35p a minute to ring another networks mobile,but by ringing say Cheapest Calls mobile access no 0871 999 17 17, it costs just 15p a minute.
If you were ringing say Portugal it would normally cost you 40p a minute but by using
Pennyphone 08452 366 366 access no it would cost you 10p a minute.
www.pennyphone.co.uk www.cheapestcalls.co.uk