# CM11

Postcode district covering Billericay, Sunnymede and South Green, in Basildon and Chelmsford.

CM11 is a postcode district covering Billericay, Sunnymede and South Green, in Basildon and Chelmsford. Median sale price £490,000 in 2025.

Postcode district. Code CM11. In: [Postcodes](https://openindex.co.uk/postcode) › [CM](https://openindex.co.uk/postcode/cm)

Approximate outline worked out by Open Index from the ONS Postcode Directory: each census output area belongs to the district that holds most of its postcodes. People, homes, recorded crime and broadband add up those output areas. House sales count every sale with an CM11 postcode. [How census figures are added up](https://openindex.co.uk/sources/population)

## Key figures

- **Median sale price: £490,000** (2025). The median price paid for a home in CM11 was £490,000 in 2025. Joint 299th most expensive of 2,235. Source: Worked out by Open Index from HM Land Registry Price Paid Data. Published 28 September 2026. https://openindex.co.uk/postcode/cm11#f-house-sales-median-price
- **Population: 19,148** (2021). CM11 had 19,148 usual residents at the census (ONS Census 2021). 1,238th least populated of 2,756. Source: Census 2021, England and Wales and Scotland's Census 2022 and Census 2021, Northern Ireland, 2021. Published 21 July 2026. https://openindex.co.uk/postcode/cm11#f-population
- **People in radon Affected Area squares: 0%** (2022). About 0% of people in CM11 live in a 1 km square that the radon atlas marks as a radon Affected Area. UK 44%. Source: Worked out by Open Index from the UKHSA and BGS radon atlas and census output areas. Published 1 December 2022. https://openindex.co.uk/postcode/cm11#f-radon-affected-share
- **Gigabit broadband coverage: 87.6%** (January 2026). In CM11, 87.6% of homes and businesses could get gigabit-capable broadband in January 2026 (Ofcom). UK 87.8%. Source: Connected Nations (Ofcom), January 2026. Published 13 May 2026. https://openindex.co.uk/postcode/cm11#f-gigabit-coverage

## On the map

- [Radon Affected Area by postcode district](https://openindex.co.uk/map/radon-affected-areas?place=CM11) (Worked out by Open Index · 2022): About 0% of people in CM11 live in a 1 km square that the radon atlas marks as a radon Affected Area.
- [Sales per year by postcode district](https://openindex.co.uk/map/house-sales-per-year?place=CM11) (Worked out by Open Index · 2025): 298 homes were sold in CM11 in 2025.
- [Crime and ASB by postcode district](https://openindex.co.uk/map/recorded-crime?place=CM11) (Police recorded crime and outcomes (data.police.uk) · August 2026): Crime and anti-social behaviour for CM11.
- [Population by postcode district](https://openindex.co.uk/map/population?place=CM11) (Census 2021, England and Wales): CM11 had 19,148 usual residents at the census.

## How CM11 compares

Each postcode district against every other postcode district the measure covers.

| Measure | CM11 | Rank | Compared with |
| --- | --- | --- | --- |
| Median sale price | £490,000 | joint 6th most expensive | 25 postcode districts, CM · 2025 |
| Population | 19,148 | 10th least populated | 27 postcode districts, CM · 2021 |
| People in radon Affected Area squares | 0% | joint fewest people in radon Affected Areas | 27 postcode districts, CM · 2022 |
| Gigabit broadband coverage | 87.6% | 11th lowest | 27 postcode districts, CM · Jan 2026 |

## Is CM11 safe? What police records show

In the 12 months to August 2026, police recorded crimes and anti-social behaviour in CM11 at a rate of 37.7 per 1,000 people.
That compares with 77.3 per 1,000 people across the CM postcode area.
In August 2026 alone, 43 cases of crime and anti-social behaviour were recorded in CM11.
In the 12 months to August 2026, the most common types were violence and sexual offences (328), other crime (140) and criminal damage and arson (65).
A year earlier, the recorded crime rate in CM11 was 36.6 per 1,000 people.
Worked out by Open Index from police.uk crime records and ONS and NISRA population estimates.
Rates are per resident, so places that many people work in or visit, such as Westminster, the City of London and other city centres, have far higher rates than their residents alone would suggest.

## Deprivation in CM11, neighbourhood by neighbourhood

- Deprivation is ranked by neighbourhood, so CM11 has no single figure. Of its 13 neighbourhoods with a rank:
- Decile 3: 1 neighbourhood
- Decile 5: 2 neighbourhoods
- Decile 7: 1 neighbourhood
- Decile 8: 3 neighbourhoods
- Decile 9: 2 neighbourhoods
- Decile 10 (England’s least deprived 10%): 4 neighbourhoods

Source: English Indices of Deprivation 2025. Decile 1 is the most deprived tenth of neighbourhoods in England.

## Neighbourhoods in CM11

| Area | People (census) | Recorded crime per 1,000 | Deprivation decile | Gigabit broadband |
| --- | --- | --- | --- | --- |
| [Basildon 001A](https://openindex.co.uk/basildon/neighbourhood/e01021237) | 1,367 | 22.0 per 1,000 | 10 | 55.7% |
| [Basildon 001B](https://openindex.co.uk/basildon/neighbourhood/e01021238) | 1,367 | 16.8 per 1,000 | 10 | 97.7% |
| [Basildon 001C](https://openindex.co.uk/basildon/neighbourhood/e01021242) | 1,252 | 30.6 per 1,000 | 9 | 91.0% |
| [Basildon 003A](https://openindex.co.uk/basildon/neighbourhood/e01021239) | 1,450 | 15.4 per 1,000 | 10 | 99.1% |
| [Basildon 003B](https://openindex.co.uk/basildon/neighbourhood/e01021240) | 1,769 | 62.2 per 1,000 | 8 | 68.7% |
| [Basildon 003C](https://openindex.co.uk/basildon/neighbourhood/e01021241) | 1,714 | 50.3 per 1,000 | 5 | 98.7% |
| [Basildon 003D](https://openindex.co.uk/basildon/neighbourhood/e01021243) | 1,669 | 26.3 per 1,000 | 10 | 98.8% |
| [Basildon 004E](https://openindex.co.uk/basildon/neighbourhood/e01021258) | 1,712 | 66.4 per 1,000 | 5 | 92.7% |
| [Basildon 006A](https://openindex.co.uk/basildon/neighbourhood/e01021264) | 1,467 | 36.9 per 1,000 | 7 | 78.9% |
| [Basildon 009B](https://openindex.co.uk/basildon/neighbourhood/e01021257) | 1,571 | 40.7 per 1,000 | 9 | 91.4% |
| [Basildon 009C](https://openindex.co.uk/basildon/neighbourhood/e01021259) | 1,550 | 38.6 per 1,000 | 8 | 99.1% |
| [Basildon 009D](https://openindex.co.uk/basildon/neighbourhood/e01021260) | 1,821 | 78.7 per 1,000 | 3 | 64.0% |
| [Chelmsford 018D](https://openindex.co.uk/chelmsford/neighbourhood/e01021604) | 2,332 | 34.5 per 1,000 | 8 | 90.1% |

## Your MP

- [Basildon and Billericay](https://openindex.co.uk/constituency/basildon-and-billericay): Mr Richard Holden (Conservative), MP since July 2024. 82% of the people here.
- [Maldon](https://openindex.co.uk/constituency/maldon): Sir John Whittingdale (Conservative), MP since July 2024. 18% of the people here.

As of 18 October 2026. Contains Parliamentary information licensed under the Open Parliament Licence v3.0. Source: UK Parliament, Members API.

## Middle areas in CM11

[Billericay Central & Sunnymede](https://openindex.co.uk/basildon/billericay-central-and-sunnymede), [Billericay North East](https://openindex.co.uk/basildon/billericay-north-east), [Bursteads](https://openindex.co.uk/basildon/bursteads)

## Postcode sectors in CM11

[CM11 1 (181 postcodes)](https://openindex.co.uk/postcode/cm11-1), [CM11 2 (272 postcodes)](https://openindex.co.uk/postcode/cm11-2)

## Councils CM11 covers

[Basildon](https://openindex.co.uk/basildon), [Chelmsford](https://openindex.co.uk/chelmsford)

## Towns in CM11

[Billericay](https://openindex.co.uk/town/billericay)

## Postcode districts next to CM11

[CM3](https://openindex.co.uk/postcode/cm3), [CM4](https://openindex.co.uk/postcode/cm4), [CM12](https://openindex.co.uk/postcode/cm12), [SS12](https://openindex.co.uk/postcode/ss12), [SS14](https://openindex.co.uk/postcode/ss14), [SS15](https://openindex.co.uk/postcode/ss15)

## Nearest rail stations

[Billericay (3.0 km from the middle)](https://openindex.co.uk/map/rail-stations?around=0.4186,51.6289), [Wickford (4.2 km from the middle)](https://openindex.co.uk/map/rail-stations?around=0.5192,51.6150), [Basildon (5.5 km from the middle)](https://openindex.co.uk/map/rail-stations?around=0.4568,51.5681)

## More in the CM postcode area

[All CM postcode districts](https://openindex.co.uk/postcode/cm), [Every UK postcode area](https://openindex.co.uk/postcode)

## CM11 in brief

CM11 is a postcode district covering Billericay, Sunnymede and South Green, in Basildon and Chelmsford.
About 19,276 people lived in CM11 in mid-2024 (worked out by Open Index from ONS small-area estimates); the median price paid for a home was £490,000 in 2025 across 298 sales (HM Land Registry) and police recorded crimes and anti-social behaviour at a rate of 37.7 per 1,000 people in the 12 months to August 2026 (police.uk).
The median price paid for a home in CM11 was £490,000 in 2025.
CM11 had 19,148 usual residents at the census.
About 0% of people in CM11 live in a 1 km square that the radon atlas marks as a radon Affected Area.
In CM11, 87.6% of homes and businesses could get gigabit-capable broadband in January 2026.

## About

- Type: Postcode district
- Code: CM11
- Postcode area: [CM](https://openindex.co.uk/postcode/cm)
- Constituency: [Basildon and Billericay †](https://openindex.co.uk/constituency/basildon-and-billericay)
- Council: [Basildon †](https://openindex.co.uk/basildon)
- Area: 26.23 km²
- People, mid-2024: 19,276*
- Neighbourhoods: 13
- Output areas: 58

* People: worked out by Open Index from neighbourhood estimates, shared out by where people lived at the census (by area in Northern Ireland). This area's edges do not follow neighbourhood edges, so the figure is close but not exact.
† Best fit: the constituency, council, region and nation this postcode district mostly lies in. Its edges do not follow theirs.

## Next door

[CM12](https://openindex.co.uk/postcode/cm12), [CM3](https://openindex.co.uk/postcode/cm3), [CM4](https://openindex.co.uk/postcode/cm4), [SS12](https://openindex.co.uk/postcode/ss12), [SS15](https://openindex.co.uk/postcode/ss15), [SS14](https://openindex.co.uk/postcode/ss14)

## Latest updates for CM11

- August 2026 house prices published: HM Land Registry and partners · Oct 2026.
- September 2026 rent published: ONS private rents · Oct 2026.
- Dental practices updated: NHS England · Oct 2026.
- Schools updated: Ofsted · Oct 2026.

The same figures as JSON: https://openindex.co.uk/v1/places/CM11

## How to cite

Source: Open Index, openindex.co.uk. Link to this page, https://openindex.co.uk/postcode/cm11, or to one figure with its anchor, https://openindex.co.uk/postcode/cm11#f-house-sales-median-price.

Open Index's own text and the figures it works out are licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source data keeps its publishers' licences, named with each figure. Give each figure's period and source with it.

Snapshot 2026.10.9. The HTML page: https://openindex.co.uk/postcode/cm11