Every home that pays council tax sits in a valuation band, and that band — not what your home is worth today — decides your bill. The system is simpler than it looks once you know two things: where the bands came from, and how they relate to each other.
Where the bands came from
When council tax replaced the poll tax in 1993, every home in England and Scotland was assigned a band based on its estimated market value on 1 April 1991. Those 1991 values are still the basis of your band today, which is why a modest terrace and its identical neighbour can only differ in band if the valuers judged them differently three decades ago. Wales is the exception: it revalued in 2003 and added a ninth band, so Welsh homes are banded A–I on 2003 values.
The ninths arithmetic
Bands are not independent price lists — each one is a fixed fraction of Band D, counted in ninths. Band A is 6/9 of the Band D charge, Band B is 7/9, C is 8/9, D is 9/9, E is 11/9, F is 13/9, G is 15/9 and H is exactly double at 18/9. Wales's Band I pays 21/9. So when a council publishes only its Band D figure, every other band follows mechanically — that is how we compute full tables where a council publishes precepts rather than a per-band grid, and every derived table is arithmetic-checked to the penny.
Scotland kept the same A–H structure but raised the multipliers for bands E–H in April 2017, so higher-band Scottish homes pay proportionately more than the old ninths would suggest. Scottish bills also work differently in another way: water and sewerage are charged on top.
What your bill actually includes
The figure on your bill is usually a stack of precepts: the main council, plus police, fire, and sometimes a mayoral authority or a parish council. Councils present these differently, which is a major source of wrong figures online — we wrote about why. Every figure on this site states what it includes and links to the council's own page.
Find your own numbers
Look up your council's full table with the band checker, work out your bill with the calculator, or browse all 350 councils. If you suspect your 1991 valuation put you in the wrong band, you can challenge it.