AL4 postcode district

Postcodes and sectors

787 of the district's 1,059 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 51.77378, -0.29475, which locates the district, not a building.

Companies registered in AL4

Companies House lists 1,986 companies with a registered office in AL4; 224 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 AL4

• Hertfordshire
• Eastern
• St. Albans
• St Albans
• Wheathampstead
• Sandridge
• Colney Heath
• Blackmore End
• Lea Valley
• Smallford
• North Hertfordshire
• Welwyn Hatfield
• Tyttenhanger
• Sleapshyde
• Gustard Wood
• The Folly
• Hertsmere
• Nomansland
• Coleman Green
• Amwell
• Cooper's Green

Roads filed under AL4

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.

• Abbot John Mews
• Acrewood Park
• Acrewood Way
• Admirals Close
• Alban Park
• Alban Way
• Aldbury Close
• Allen Close
• Allen Green
• Amwell Lane
• Anson Close
• Ardens Marsh
• Ardens Way
• Ash Grove
• Austen Way
• Ayot Greenway
• Ballslough Hill
• Barley Close
• Barley Mow Lane
• Barnfield Road
• Barton Road
• Battleview
• Beech Crescent
• Beech Farm Drive
• Beech Hyde Lane
• Beech Way
• Belgrave Close
• Bell View
• Belsize Close
• Bennetts Close
• Bentsley Close
• Berkley Close
• Beverley Gardens
• Bishop's Close
• Bishop's Garth
• Blackmore Manor
• Blackmore Way
• Blackthorn Close
• Boissy Close
• Boling Brook
• Bramley Way
• Brecken Close
• Brewhouse Hill
• Briar Road
• Brocket View
• Bronte Close
• Broomleys
• Brownfield Way
• Bryn Way
• Bullen's Green Lane
• Bull Lane
• Burton Close
• Bury Green
• Butterfield Road
• Buxton Close
• Caesars Road
• Cairns Close
• Canons Field
• Castle Rise
• Cedar Court

Check an address in AL4

Check an address in AL4

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=AL4" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about AL4

What does an AL4 postcode tell you?

That the address lies in the AL4 district of the AL (St Albans) postcode area, and the place OS Open Names most often lists first for its postcodes is St Albans. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 787 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 AL4

• AL13.4 km
• AL104.5 km
• AL35.8 km
• AL56.1 km
• AL86.6 km
• AL26.7 km
• AL97.5 km
• AL77.8 km
• AL69.2 km
• WD79.7 km
• HP210.9 km
• WD511.5 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids