UK Postcode Lookup

A UK postcode lookup resolves a postcode or outward code to the post town, county and country it belongs to, and breaks the postcode into its area, district, sector and unit.

The lookup accepts a full postcode (SW1A 1AA), an outward code (M20), a postcode area (BT) or a post-town name (Cardiff), and returns the matching geography from the curated registry along with a structural breakdown of the postcode. When there is no match it says so rather than inventing a result, which matters for a reference tool.

Options

NameTypeDefaultDescription
qstring—Postcode, outward code, postcode area or post town.

Use cases

  • Understanding a postcode: See exactly which characters form the area, district, sector and unit, and which format the postcode matches.
  • Checking district coverage: List every postcode district served by a post town before writing delivery-zone rules.
  • Debugging address matching: Confirm whether a district genuinely belongs to the post town an address claims.

REST API

GET /api/v1/postcodes/lookup

curl "https://ukaddressgenerator.org/api/v1/postcodes/lookup?q=M20"
{
  "status": "success",
  "data": {
    "query": "M20",
    "found": true,
    "outwardCode": "M20",
    "area": "M",
    "district": "M20",
    "postTown": "MANCHESTER",
    "locality": "Didsbury",
    "county": "Greater Manchester",
    "country": "England",
    "region": "North West England",
    "diallingCode": "0161",
    "latitude": 53.4808,
    "longitude": -2.2426
  }
}

Frequently asked questions

Is this a Royal Mail PAF lookup?

No. It reports postcode structure and the relationship between a district and its post town using a curated registry. It cannot confirm that an individual property exists — that requires a licensed Postcode Address File provider.

What can I search for?

A full postcode, an outward code such as M20, a postcode area such as BT, or a post-town name such as Cardiff.

Why does a valid postcode sometimes return no match?

The registry covers a curated set of post towns. A structurally valid postcode in a district outside that set is reported as valid but unmatched, rather than being guessed at.

Related tools