CM4 postcode district

Postcodes and sectors

442 of the district's 616 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 51.67511, 0.38938, which locates the district, not a building.

Companies registered in CM4

Companies House lists 1,335 companies with a registered office in CM4; 520 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 CM4

• Essex
• Eastern
• Brentwood
• Chelmsford
• Ingatestone
• Stock
• Blackmore
• Margaretting
• Epping Forest
• Mill Green
• Beggar Hill
• Norton Heath
• Nine Ashes
• Fryerning
• Billericay
• Basildon
• Paslow Wood Common
• Margaretting Tye
• Hook End
• Green Street
• Handley Green
• Tye Green

Roads filed under CM4

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.

• Ashridge Grange
• Ash Tree Grove
• Austen Drive
• Avenue Road
• Back Lane
• Bag Lane
• Bakers Field
• Bakers Lane
• Bakers Mews
• Barking Close
• Barrington Place
• Beggarhill
• Bell Mead
• Birch Lane
• Blackmore Mead
• Blackmore Road
• Blacksmiths Alley
• Brittons Lane
• Brookmans Road
• Brookmans View
• Broomwood Lane
• Burnthouse Lane
• Buttsbury
• Buttsbury Drive
• Cambridge Close
• Cameron Close
• Canon Hudson Gardens
• Catcher Court
• Chantry Drive
• Chapel Croft
• Chelmsford Road
• Chestnut Court
• Church Lane
• Church Street
• Common Lane
• Common Road
• Court View
• Crondon Park Lane
• Crown Mews
• Dakyn Drive
• Deepdene
• Dengie Gardens
• Disney Close
• Docklands Avenue
• Dog Kennel Lane
• Downham Road
• Durham Crescent
• Edward Court
• Elston Court
• Exley Close
• Fairfield
• Falkner Close
• Fallowfield Crescent
• Fingrith Hall Lane
• Fitzroy Close
• Fosters Close
• Foxborough Chase
• Fryerning Lane
• Furze Lane
• Garden End

Check an address in CM4

Check an address in CM4

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=CM4" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about CM4

What does a CM4 postcode tell you?

That the address lies in the CM4 district of the CM (Chelmsford) postcode area, and the place OS Open Names most often lists first for its postcodes is Ingatestone. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 442 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 CM4

• CM125.5 km
• CM156.8 km
• CM117.0 km
• CM137.6 km
• CM28.4 km
• CM149.2 km
• CM19.3 km
• CM511.0 km
• SS1511.2 km
• SS1211.9 km
• SS1112.1 km
• CM9812.3 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids