The LUS line rental is £34.50/quarter - the same as BT Together Option 1.
Of course, you do get the discounts here if you don't use the line..
I think you've misunderstood what's meant by 'prefix' in my earlier post. The examples you mention are part of the phone number. The ones I'm referring to are added to the start of a phone number in order to route the call over another operator's network. 18866 is an example that gets discussed here rather a lot. There's less need for this sort of thing now with Carrier Pre-Selection.
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