In message , at 11:36:51 on Mon,
22 Jul 2019, Natalie Amery remarked:

Actually the ways that ofcom charge for number blocks are many and
confusing. Including a proposal (I don't know if it went anywhere)
that they would charge for _unused_ numbers in allocations...

That sound a bit like double council tax for homes left empty. In other
words, pursuing a public policy objective and nothing at all to do with
"cost-plus" accounting.
--
Roland Perry