CO4 postcode district

Postcodes and sectors

1,193 of the district's 1,722 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 51.90927, 0.91907, which locates the district, not a building.

Companies registered in CO4

Companies House lists 4,074 companies with a registered office in CO4; 1,294 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 CO4

• Colchester
• Essex
• Eastern
• Boxted
• Langham
• Tendring
• Boxted Cross
• Workhouse Hill
• Hornestreet

Roads filed under CO4

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 Avenue
• Accommodation Road
• Achnacone Drive
• Acorn Close
• Aerofoil Grove
• Affleck Road
• Alba Mews
• Albrighton Croft
• Aldeburgh Gardens
• Alderton Road
• Alefounder Close
• Alexander Court
• Alistair Day Way
• Almond Way
• Altius Chase
• Alverton Way
• Alyssum Walk
• Amelia Chase
• Anemone Court
• Annan Road
• Anthony Close
• Antonio Walk
• Antonius Way
• Appleton Mews
• Apprentice Drive
• Arbour Way
• Arden Close
• Ariel Close
• Armada Drive
• Arnold Drive
• Arnstones Close
• Arrow Road
• Arrowsmith Walk
• Arthur Cross Square
• Asbury Close
• Ascot Drive
• Ashdown Way
• Ashley Row
• Aspen Way
• Asquith Drive
• Attwood Close
• Augustus Close
• Autoway
• Avitus Way
• Avondene Drive
• Avon Way
• Axial Drive
• Axial Way
• Ayloffe Road
• Baker's Lane
• Balfe Court
• Ballerina Walk
• Barbel Road
• Bardsley Close
• Barfoot Drive
• Barkstead Road
• Barnardiston Road
• Barncroft Close
• Baronia Croft
• Bartholomew Court

Check an address in CO4

Check an address in CO4

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=CO4" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about CO4

What does a CO4 postcode tell you?

That the address lies in the CO4 district of the CO (Colchester) postcode area, and the place OS Open Names most often lists first for its postcodes is Colchester. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 1,193 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 CO4

• CO13.1 km
• CO24.8 km
• CO35.1 km
• CO76.6 km
• CO69.0 km
• CO1111.4 km
• CO512.5 km
• CO812.7 km
• CO1617.1 km
• IP717.8 km
• IP917.9 km
• IP820.3 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids