+44-20-(36710000...36719999): London, City of London (LND) Read more about +44-20-(36710000...36719999)
+44-8435-(250000...259999): Special Services basic rate: up to and including 5p for BT customers (non-internet) Read more about +44-8435-(250000...259999)
+44-8451-(970000...979999): Special Services basic rate: BT’s Standard Local Call Retail Price for BT customers Read more about +44-8451-(970000...979999)
+44-8712-(010000...019999): Special Services higher rate: up to and including 10p for BT customers (non-internet) Read more about +44-8712-(010000...019999)
+44-121-(0120000...0129999): Birmingham, Birmingham (BIR) Read more about +44-121-(0120000...0129999)