CO1 postcode district

Postcodes and sectors

593 of the district's 1,164 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 51.88454, 0.89741, which locates the district, not a building.

Companies registered in CO1

Companies House lists 2,036 companies with a registered office in CO1; 415 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 CO1

• Colchester
• Essex
• Eastern
• Tiptree

Roads filed under CO1

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.

• Albert Street
• Arclight Way
• Artillery Street
• Balkerne Close
• Balkerne Gardens
• Ball Alley
• Bank Passage
• Barcro Square
• Barrack Street
• Belle Vue Road
• Belmont Place
• Bloyes Mews
• Bretts Buildings
• Bristol Road
• Brooklands
• Brook Street
• Bury Close
• Cannon Road
• Cannon Street
• Carlisle Close
• Castle Bailey
• Castle Road
• Catchpool Road
• Causton Road
• Challenge Way
• Chandlers Row
• Charles Street
• Childwell Alley
• Chiltern Close
• Church Street
• Church Walk
• Claremont Heights
• Clarendon Way
• Coalville Mews
• Colne Bank Avenue
• Connaught Close
• Coventry Close
• Cowdray Avenue
• Cowdray Crescent
• Cross Cut Court
• Culver Street East
• Culver Street West
• Culver Walk
• Dairy Close
• Davey Close
• Durham Square
• Eaglegate
• East Bay
• East Hill
• East Stockwell Street
• East Street
• East Ward Mews
• Edward Paxman Gardens
• Eld Lane
• Ely Gardens
• Ernulph Walk
• Essex Hall Road
• Exeter Drive
• Falcon Crescent
• Farrington Close

Check an address in CO1

Check an address in CO1

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=CO1" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about CO1

What does a CO1 postcode tell you?

That the address lies in the CO1 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 593 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 CO1

• CO21.7 km
• CO32.9 km
• CO43.1 km
• CO77.4 km
• CO68.6 km
• CO59.4 km
• CO813.4 km
• CO1113.9 km
• CO1617.0 km
• CM819.9 km
• CO1520.2 km
• IP920.6 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids