CM12 postcode district

Postcodes and sectors

507 of the district's 843 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 51.62838, 0.41440, which locates the district, not a building.

Companies registered in CM12

Companies House lists 3,402 companies with a registered office in CM12; 1,139 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 CM12

• Essex
• Eastern
• Basildon
• Billericay
• Little Burstead
• Noak Hill
• Havering's Grove
• Brentwood

Roads filed under CM12

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.

• Abbey Road
• Allysum Walk
• Alma Link
• Anvil Way
• Archers Close
• Arlington Way
• Arundel Close
• Arundel Mews
• Arundel Way
• Atridge Chase
• Beaufort Road
• Bebington Close
• Belgrave Road
• Bellevue Road
• Bell Farm Green
• Bell Hill Close
• Beresford Court
• Berkeley Drive
• Betony Crescent
• Blacksmith Close
• Blind Lane
• Bluebell Wood
• Blunts Wall Road
• Boleyn Close
• Bootham Close
• Bootham Road
• Botney Hill Road
• Brandon Close
• Brightside
• Brightside Close
• Brompton Close
• Broomhills Chase
• Buckwyns
• Burghstead Close
• Burleigh Close
• Burntwood Close
• Bush Hall Road
• Buttercup Close
• Carlyle Gardens
• Carpenter Close
• Cater Wood
• Celandine Close
• Central Avenue
• Centurion Way
• Chapel Court
• Chapel Mews
• Chapel Street
• Charity Farm Chase
• Cherry Gardens
• Cherrytrees
• Chestnut Avenue
• Chestwood Close
• Clock House Road
• Colosseum Square
• Colville Mews
• Connaught Way
• Coombes Close
• Cornflower Gardens
• Courtlands
• Coxbridge Court

Check an address in CM12

Check an address in CM12

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=CM12" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about CM12

What does a CM12 postcode tell you?

That the address lies in the CM12 district of the CM (Chelmsford) postcode area, and the place OS Open Names most often lists first for its postcodes is Billericay. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 507 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 CM12

• CM112.3 km
• CM135.5 km
• CM45.5 km
• SS155.7 km
• SS147.2 km
• SS167.8 km
• SS127.8 km
• CM157.9 km
• CM148.5 km
• SS118.6 km
• SS138.9 km
• CM211.4 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids