SE21 postcode district: Southwark and around

SE21 is a postcode district in England, with 296 postcodes in use in 3 sectors. It has postcodes in Southwark and Lambeth. It is split between 2 councils: Southwark (181 postcodes) and Lambeth (115).

Postcodes in use: 296
Sectors: 3
Councils: 2 councils
Places: 2 places

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026. See all our data sources

Every postcode in SE21, and which are new since 2020

New since 2020: 11
In use before 2020: 285
Outline: where 5 or more new postcodes since 2020 lie together

Of the 296 postcodes in SE21 that ONS places, 11 are new since 2020 and 285 were in use before 2020.

Each mark is a postcode's centre point as ONS gives it, not a building. Press one to see its postcode and open its page. New since 2020 means it came into use in January 2020 or later. A dashed outline shows where 5 or more lie within 150 metres of each other. It is not a boundary, and no boundary is drawn. Where marks overlap, the one first in the key is drawn; the counts include every postcode. Names in italics are council wards: we hold no town or village names here.

The middle of its postcodes: latitude 51.4390, longitude -0.0887. Open this area on OpenStreetMap

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026, the centre point of each postcode; when each came into use: the same directory; roads, rivers and built-up areas: Contains OS data © Crown copyright and database right 2026. Drawn by us. Street map: Ordnance Survey, OS Open Zoomstack, Open Government Licence v3.0, drawn with MapLibre. How we use them

The 5 newest postcodes

SE21 9EAMay 2026 SE21 9DZJanuary 2026 SE21 9DYDecember 2025 SE21 9DWDecember 2024 SE21 7AUApril 2024

Where the new postcodes lie together

8 new postcodes since 2020, outlined on the map. SE21 9EA, is the newest of them.

What broadband can you get in SE21?

Ofcom reports on 281 of the 296 postcodes in SE21. At 207 of them every home and business can get gigabit broadband.

Postcodes where every home can get gigabit207 of 281

Postcodes where every home can get superfast264 of 281

Ofcom gives each postcode's share of homes and businesses, not how many there are, so these count postcodes. Each postcode page has its own figures. A provider's checker answers for one address.

Check one address on Ofcom's checker

Source: Ofcom, Connected Nations, Spring 2026, data for January 2026, Open Government Licence v3.0. How we use it

Is SE21 at risk of flooding?

None of the 296 postcodes in SE21 is on the Environment Agency's list of postcodes with a home or business in an area at risk of flooding from rivers or the sea.

Homes and businesses in an area at risk of flooding from rivers or the sea, as the Environment Agency counts them, added up over the postcodes. It is for the land, not each building, and leaves out surface water, groundwater and sewers. Each postcode page has its own figures and its flood warning areas.

Source: Environment Agency, Risk of Flooding from Rivers and Sea (postcodes in areas at risk), published 6 July 2026, Open Government Licence v3.0. How we use it

What do homes sell for in SE21?

Homes in SE21 sold for a typical £730,000 in the 12 months to August 2026, across 128 sales, down 0.7% on the 12 months before, HM Land Registry's figures show.

£730,000 typical price, the 12 months to August 2026

£735,000 12 months to August 2025

▼ down 0.7% on the 12 months before

Detached £2,150,000 5 sales
Semi-detached £1,375,000 30 sales
Terraced £902,500 36 sales
Flat or maisonette £405,000 57 sales

Each bar is that kind's typical price, against the most expensive kind here.

Standard sales of homes at market value. A typical price is the median, the middle sale. Sales take weeks to be registered, so the last month or two are incomplete. Each postcode page gives the figure for its own postcode sector.

Source: HM Land Registry Price Paid Data, files dated 28 September 2026. Contains HM Land Registry data © Crown copyright and database right 2021. This data is licensed under the Open Government Licence v3.0. How we use it