I would like to add one other useful document:
http://www.cabinetoffice.gov.uk/media/218872/numbering_clarification.pdf - The Contact Council exists to represent and serve all public sector bodies.
There is some dispute about whether the technical benefits provided by use of non-geographic even exist, and if they provide true value for money.
If they do, then the question is about where the money comes from. In this case it is either service users (who call) or Council Tax-payers who otherwise provide the funding for Council services. With 084 numbers, callers pay (indirectly) through the revenue share. With 03 numbers, there can be no premium added to the call charge, so the cost of extra features has to be met out of the Council's budget.
The issue is complicated by the fact that one telephone company (BT) is not permitted to make a profit on placing calls to 084 numbers, and so its charges can appear relatively low. This regulation does not affect other providers, who do pass on the cost of the subsidy provided through revenue sharing. This regulation should now be removed.and it will indeed be reviewed shortly.