CM20 postcode district: Harlow and around
CM20 is a postcode district mostly in Essex, with 629 postcodes in use in 4 sectors. It has postcodes in Harlow. It is split between 2 councils: Harlow (597 postcodes) and East Hertfordshire (32). 597 are in Essex and 32 in Hertfordshire.
- Postcodes in use
- 629
- Sectors
- 4
- Councils
- 2 councils
- Places
- Harlow
Source: ONS Postcode Directory, August 2026, loaded 20 October 2026.
Every postcode in CM20, by gigabit broadband
- No home or business can get gigabit: 138
- Some can get gigabit: 98
- Every home and business can get gigabit: 310
- Ofcom gives no figure: 83
- Outline: where 5 or more postcodes without gigabit lie together
Of the 629 postcodes in CM20 that ONS places, 138 have no home or business that can get gigabit, 98 have some that can, 310 can all get it and 83 have no Ofcom figure.
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. 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 51.7757, longitude 0.1028. Open this area on OpenStreetMap
Sources: ONS Postcode Directory, August 2026, loaded 20 October 2026; Ofcom Connected Nations, Connected Nations, Spring 2026; roads, rivers and built-up areas: Ordnance Survey open maps. 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.
Postcodes without gigabit
138 postcodes here have no gigabit. These are the 12 first in postcode order.
3 further out, not drawn
These postcodes lie well apart from the rest, so the map is drawn without them to show the rest closer; they are in every count.
Where the postcodes without gigabit lie together
- 39 postcodes without gigabit, outlined on the map. CM20 1JD, is the one nearest the middle of them.
- 29 postcodes without gigabit, outlined on the map. CM20 2BH, is the one nearest the middle of them.
- 8 postcodes without gigabit, outlined on the map. CM20 2DR, is the one nearest the middle of them.
- 8 postcodes without gigabit, outlined on the map. CM20 2JG, is the one nearest the middle of them.
- 6 postcodes without gigabit, outlined on the map. CM20 2QX, is the one nearest the middle of them.
- 5 postcodes without gigabit, outlined on the map. CM20 3AB, is the one nearest the middle of them.
What broadband can you get in CM20?
Ofcom reports on 546 of the 629 postcodes in CM20. At 310 of them every home and business can get gigabit broadband, and at 1 some cannot get decent broadband (10 Mbit/s).
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 checkerSource: Ofcom Connected Nations, Connected Nations, Spring 2026, data for January 2026.
Is CM20 at risk of flooding?
23 of the 629 postcodes in CM20 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 124 homes and businesses in an area at high or medium risk.
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 flood risk, published 6 July 2026.
What do homes sell for in CM20?
Homes in CM20 sold for a typical £325,000 in the 12 months to September 2026, across 194 sales, HM Land Registry's figures show. The 12 months before gave £315,000 from 256 sales: not a change larger than chance would explain, given which homes happened to sell.
- Detached £610,000 11 sales
- Semi-detached £408,750 14 sales
- Terraced £336,954 96 sales
- Flat or maisonette £200,000 73 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 October 2026.
Postcodes in CM20
Pick a sector, then a postcode. A sector is the district plus the next digit.
UK postcode format explainedPlaces in CM20
Towns and villages with postcodes in CM20, and how many each has here.
Who covers CM20
How many of the district's postcodes in use fall under each council, constituency and police force area.
Councils
What council am I in?Constituencies
- Harlow597
- Hertford and Stortford32
Police force areas
- Essex597
- Hertfordshire32
Next to CM20
"Next to" is by number: the districts before and after CM20 in the CM area.
Check a postcode
Where the facts on this page come from
- Office for National Statistics: ONS Postcode Directory
- Ofcom Connected Nations
- Environment Agency flood risk
- HM Land Registry Price Paid Data
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2021. This data is licensed under the Open Government Licence v3.0.
Licence: Open Government Licence v3.0.
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