CM23 postcode district: Bishop's Stortford and around

CM23 is a postcode district mostly in Hertfordshire, with 1,200 postcodes in use in 7 sectors. It has postcodes in Bishop's Stortford and Stansted Mountfitchet. It is split between 2 councils: East Hertfordshire (1,100 postcodes) and Uttlesford (100). 1,100 are in Hertfordshire and 100 in Essex.

Postcodes in use: 1,200
Sectors: 7
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 CM23, and which are new since 2020

New since 2020: 190
In use before 2020: 1,010
Outline: where 5 or more new postcodes since 2020 lie together

Of the 1,200 postcodes in CM23 that ONS places, 190 are new since 2020 and 1,010 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.

The middle of its postcodes: latitude 51.8728, longitude 0.1580. 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

CM23 0DNJuly 2026 CM23 0AFJune 2026 CM23 0ARJune 2026 CM23 0BAJune 2026 CM23 0BWJune 2026

Where the new postcodes lie together

43 new postcodes since 2020, outlined on the map. CM23 0DN, is the newest of them.
41 new postcodes since 2020, outlined on the map. CM23 1GN, is the newest of them.
25 new postcodes since 2020, outlined on the map. CM23 4SP, is the newest of them.
16 new postcodes since 2020, outlined on the map. CM23 2AF, is the newest of them.
15 new postcodes since 2020, outlined on the map. CM23 4TL, is the newest of them.
11 new postcodes since 2020, outlined on the map. CM23 2AW, is the newest of them.

What broadband can you get in CM23?

Ofcom reports on 1,119 of the 1,200 postcodes in CM23. At 779 of them every home and business can get gigabit broadband, and at 1 some cannot get decent broadband (10 Mbit/s).

Postcodes where every home can get gigabit779 of 1,119

Postcodes where every home can get superfast1,055 of 1,119

Postcodes where some cannot get decent broadband1 of 1,119

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 CM23 at risk of flooding?

115 of the 1,200 postcodes in CM23 have a home or business in an area at risk of flooding from rivers or the sea, the Environment Agency says. At those, it puts 277 homes and businesses in an area at high or medium risk.

Homes and businesses in an area at risk, at 115 of 1,200 postcodes High: 174Medium: 103Low: 754Very low: 5

High: 3.3% or more a year (1 in 30). Medium: 1% to 3.3% a year. Low: 0.1% to 1% a year. Very low: under 0.1% a year (1 in 1,000). Each band is the chance of flooding in any one year.

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 CM23?

Homes in CM23 sold for a typical £425,000 in the 12 months to August 2026, across 538 sales, down 4.7% on the 12 months before, HM Land Registry's figures show.

£425,000 typical price, the 12 months to August 2026

£446,000 12 months to August 2025

▼ down 4.7% on the 12 months before

Detached £645,750 153 sales
Semi-detached £448,000 158 sales
Terraced £375,000 129 sales
Flat or maisonette £253,750 98 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