CO
Postcode areaPostcode area named after Colchester, with 16 districts.
Approximate outline worked out by Open Index from the ONS Postcode Directory: the outline joins its districts’ outlines, each made of the census output areas that hold most of the district’s postcodes.
Radon Affected Area by postcode area
Worked out by Open Index · 2022
About 7% of people in CO live in a 1 km square that the radon atlas marks as a radon Affected Area.
How CO compares
Each dot is a postcode area. The black line marks the middle one.
Every postcode area ranked: median sale price, population, people in radon affected area squares and gigabit broadband coverage.
Is CO safe? What police records show
In the 12 months to August 2026, police recorded crimes and anti-social behaviour in CO at a rate of 83.5 per 1,000 people.
In August 2026 alone, 3,798 cases of crime and anti-social behaviour were recorded in CO.
In the 12 months to August 2026, the most common types were violence and sexual offences (17,467), other crime (6,843) and anti-social behaviour (4,288).
A year earlier, the recorded crime rate in CO was 78.6 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.
Postcode districts in CO
| Name | People (census) | Median sale price | Recorded crime per 1,000 |
|---|---|---|---|
| CO1Colchester, The Hythe | 18,519 | £245,000 | 203.1 per 1,000 |
| CO2Colchester, Shrub End | 41,393 | £297,000 | 100.9 per 1,000 |
| CO3Colchester, Lexden | 32,493 | £360,000 | 81.2 per 1,000 |
| CO4Colchester, Mile End | 53,410 | £325,000 | 103.5 per 1,000 |
| CO5West Mersea, Tiptree | 29,163 | £387,000 | 43.1 per 1,000 |
| CO6Coggeshall | 28,978 | £400,000 | 37.2 per 1,000 |
| CO7Brightlingsea, Wivenhoe | 34,669 | £355,000 | 48.9 per 1,000 |
| CO8Bures, Alphamstone | 2,441 | £447,500 | 49.1 per 1,000 |
| CO9Halstead, Sible Hedingham | 27,892 | £342,500 | 49.1 per 1,000 |
| CO10Sudbury | 51,379 | £325,000 | 51.8 per 1,000 |
| CO11Manningtree, Lawford | 13,910 | £370,000 | 45.3 per 1,000 |
| CO12Harwich, Upper Dovercourt | 23,424 | £255,000 | 96.0 per 1,000 |
| CO13Kirby Cross, Frinton-on-Sea | 13,125 | £335,000 | 45.7 per 1,000 |
| CO14Walton-on-the-Naze | 6,780 | £254,000 | 99.1 per 1,000 |
| CO15Clacton-on-Sea, Holland-on-Sea | 44,973 | £236,000 | 137.3 per 1,000 |
| CO16Clacton-on-Sea, Bocking's Elm | 26,822 | £290,000 | 107.0 per 1,000 |
CO in brief
The CO postcode area, named after Colchester, has 16 postcode districts.
The median price paid for a home in CO was £323,500 in 2025.
CO had 449,371 usual residents at the census.
About 7% of people in CO live in a 1 km square that the radon atlas marks as a radon Affected Area.
In CO, 81.1% of homes and businesses could get gigabit-capable broadband in January 2026.