W3 postcode district

Postcodes and sectors

1,158 of the district's 1,921 postcodes are live in the ONS Postcode Directory of August 2026. A postcode directory says whether a code is in use, never who is there. The live postcodes centre on 51.51107, -0.26753, which locates the district, not a building.

Companies registered in W3

Companies House lists 6,934 companies with a registered office in W3; 1,706 of them at addresses shared by 25 or more companies (1 October 2026 snapshot). 25 is the count at which the address lookup reports a company cluster.

Places OS Open Names lists for W3

• Greater London
• London
• Ealing
• Acton
• Brentford
• Hounslow
• Hammersmith and Fulham

Roads filed under W3

Named roads first, then numbered ones. A road is filed under one district even where it runs through several, so a street missing here may be listed under a neighbouring district — which is why the address lookup never calls a British street absent. Great Britain has no open register of buildings, so a listed road never means a building on it exists.

• Acacia Road
• Acorn Gardens
• Agnes Road
• Alfred Road
• Allan Way
• Alliance Road
• Allied Way
• Allison Road
• All Saints' Road
• Alwyn Gardens
• Amelia Close
• Anderson Close
• Armstrong Road
• Ashfield Road
• Avenue Crescent
• Avenue Gardens
• Avenue Road
• Baldwyn Gardens
• Balfour Road
• Barlow Road
• Bassington Road
• Baywillow Place
• Beardsley Way
• Beech Avenue
• Beechwood Grove
• Belgrave Close
• Berrymead Gardens
• Birch Grove
• Birkbeck Avenue
• Birkbeck Grove
• Birkbeck Road
• Boddington Gardens
• Bollo Bridge Road
• Bollo Lane
• Bowes Road
• Bradford Road
• Braid Avenue
• Brassie Avenue
• Broad Passage
• Bromyard Avenue
• Brook Close
• Brougham Road
• Brouncker Road
• Brunel Road
• Buckland Walk
• Burlington Gardens
• Burlington Mews
• Buxton Gardens
• Canada Crescent
• Canada Road
• Canham Road
• Carbery Avenue
• Carlisle Avenue
• Castle Close
• Caulfield Road
• Cecil Road
• Centre Avenue
• Cezanne Road
• Chatsworth Gardens
• Chaucer Road

Check an address in W3

Check an address in W3

The same road list through the API, from the outward code alone:

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=W3" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about W3

What does a W3 postcode tell you?

That the address lies in the W3 district of the W (West London) postcode area, and the place OS Open Names most often lists first for its postcodes is Acton. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 1,158 live postcodes.

Where the counts come from

• ons-postcode-directory · version 2026-08 · Contains ONS, OS and Royal Mail data © Crown copyright and database right 2026, Open Government Licence v3.0. Northern Ireland postcodes are excluded: their reuse needs a Land & Property Services licence.
• os-open-names · version 2026-11-01 · Contains OS data © Crown copyright and database right 2026, Open Government Licence v3.0.
• uk-companies-house · version 2026-10-01 · Companies House free company data product, Open Government Licence v3.0

What each figure means, and what a district page never says, is set out in Reading a British postcode district page; the glossary defines a postcode district, a postcode area, a postcode directory and a street register.

Data synced on 2026-11-01: the newest version among the datasets listed above.

Districts nearest W3

• W122.0 km
• W42.2 km
• W52.4 km
• W63.4 km
• NW103.6 km
• W113.6 km
• TW83.7 km
• W133.7 km
• W103.8 km
• SW134.2 km
• W144.4 km
• W74.7 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids