SE21 postcode district

Postcodes and sectors

296 of the district's 535 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 51.43896, -0.08872, which locates the district, not a building.

Companies registered in SE21

Companies House lists 1,065 companies with a registered office in SE21; 109 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 SE21

• London
• Greater London
• Southwark
• Lambeth

Roads filed under SE21

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 Grove
• Alleyn Crescent
• Alleyn Park
• Alleyn Road
• Allison Grove
• Aysgarth Road
• Berry Lane
• Birkbeck Hill
• Birkbeck Place
• Bowen Drive
• Boxall Road
• Burrow Walk
• Burtwell Lane
• Calton Avenue
• Carson Road
• Cedar Close
• Chalford Road
• Chancellor Grove
• Charles Nex Mews
• Church Approach
• Clive Passage
• Clive Road
• Coaldale Walk
• Cokers Lane
• College Gardens
• College Road
• Coney Acre
• Constable Walk
• Court Lane
• Court Lane Gardens
• Croxted Close
• Croxted Road
• Dalkeith Road
• Dalmore Road
• Damascene Walk
• Dekker Road
• Desenfans Road
• Dulwich Common
• Dulwich Village
• Eastlands Crescent
• Eastmearn Road
• Elmworth Grove
• Ferrings
• Frank Dixon Close
• Frank Dixon Way
• Gallery Road
• Gilkes Crescent
• Gilkes Place
• Glazebrook Close
• Grange Lane
• Great Brownings
• Hambledon Place
• Hamilton Road
• Hunts Slip Road
• Ildersly Grove
• Kingswood Drive
• Lairdale Close
• Leonora Tyson Mews
• Little Bornes
• Lords Close

Check an address in SE21

Check an address in SE21

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=SE21" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about SE21

What does an SE21 postcode tell you?

That the address lies in the SE21 district of the SE (South East London) postcode area, and the place OS Open Names most often lists first for its postcodes is London. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 296 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 SE21

• SE271.3 km
• SE242.0 km
• SE222.1 km
• SE192.3 km
• SW22.4 km
• SE262.7 km
• SE232.8 km
• SW163.4 km
• SE203.6 km
• SW93.8 km
• SE53.9 km
• SE154.1 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids