Guide
Postcode to council lookup, and where the boundary problems are
Updated
This site builds no lookup: the government publishes a free one that works. What matters is where a postcode is a poor proxy for a boundary, and how to tell.
Question 1
What is the postcode of the address?
The checker looks it up on postcodes.io, which serves the Office for National Statistics postcode directory, and names the council, or both councils where the area is two-tier. Only England has the two-tier structure that makes this confusing.
No postcode to hand? Choose where the address is
Email me this result
We will send you these figures and a link back to them. One email, nothing else unless you tick the box.
Use the official one
gov.uk's find your local council service takes a postcode and returns the council or councils covering it, at no cost.
Building a second one would not improve on it, and a copy of a public dataset that somebody forgets to refresh is worse than the original. The value on this page is what comes after the lookup, not the lookup.
Why a postcode is not a boundary
Postcodes are a delivery convenience, designed around rounds rather than around administrative areas, and there is no rule that a postcode sits inside one council.
Most do. A minority straddle a boundary, particularly on the edges of towns, in new developments and in rural areas where a unit covers a wide area. In those cases the lookup can be right about the postcode and wrong about your specific address.
How to tell when the answer is wrong
Compare against something you already know: which council sends the council tax bill, which name is on the bins, and which council's name appears in the electoral register correspondence.
If those disagree with the lookup, the address rather than the postcode is what matters, and the council named on the bill is the reliable answer.
New addresses
A recently built property may not yet appear cleanly in address data, which is the most common reason a lookup fails outright.
In that case use a neighbouring postcode to identify the council, then contact it directly. It will confirm from the address rather than the postcode, and it deals with new developments routinely.