CO1 postcode district
CO1 holds 593 live postcodes around Colchester, in Colchester.
Towns and villages with their centre in CO1
| # | Place | County / council | Population |
|---|---|---|---|
| 1 | Colchester | Essex | 130,245 |
Wards
| Name | Share of postcodes |
|---|---|
| Castle | 61% |
| New Town and Christ Church | 18% |
| Old Heath and The Hythe | 9% |
| Tiptree | 6% |
| Greenstead | 5% |
| Mile End | 0% |
Westminster constituencies
| Name | Share of postcodes |
|---|---|
| Colchester | 84% |
| Harwich and North Essex | 9% |
| Witham | 6% |
Deprivation
The middle postcode here sits in decile 4 of the English Index of Multiple Deprivation (2021-Census LSOAs), where decile 1 is the most deprived tenth of neighbourhoods and 10 the least. 42% of this district's postcodes sit in the most deprived three deciles, 8% in the least deprived three.
Deprivation deciles describe the LSOA neighbourhood each postcode sits in, weighted by postcodes rather than by people, because the postcode file carries no population. A district where the deprived neighbourhoods are densely populated will read better here than it would per resident.
Neighbouring districts in the CO area
CO2 · CO3 · CO4 · CO5 · CO6 · CO7 · CO8 · CO9 · CO10 · CO11 · CO12 · CO13 · CO14 · CO15 · CO16
Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Source: Office for National Statistics licensed under the Open Government Licence v3.0. Postcode data is the ONS Postcode Directory, August 2026 edition; counts are live postcodes with a usable location. Northern Ireland postcodes carry a separate licence and are not included; Scotland joins when the site's Scottish coverage does.