I can't imagine that there is too much effort, or costs, in porting over a service and yet it is a common charge by most VoIP providers who will often gain years of income from a new subscriber. Sometimes the charge is so high that it will take years to claw back the porting cost against the lower call costs. How is that justified?
And yet if you don't port in cherished numbers and select a group of new numbers from a pool of numbers available from the provider, there is no charge although none will be "nice" numbers with anything half "decent" costing many hundred of pounds, if not thousands. Anyone care to defend, IMHO, this nice little earner by suppliers?