CO1 1 postcode sector in the CO1 district

CO1 1 is a sector of the CO1 district: every postcode that starts CO1 1. It has 234 postcodes in use, 28 of them large-user postcodes. A large-user postcode is one Royal Mail gives to a single address that gets a lot of mail.

Not sure what a sector is? UK postcode format explained.

Every postcode in the CO1 1 sector, by flood risk

Map of every postcode in the CO1 1 sector, by flood risk Of the 234 postcodes in the CO1 1 sector that ONS places, 3 have a home or business at high risk, 5 are at medium risk at worst, 18 are at low risk at worst, 2 are at very low risk only and 206 are not on the Environment Agency's at-risk list. One group of postcodes at high or medium risk is outlined: 5 postcodes at high or medium risk. Places named: Colchester. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 250 m. A134 CO1 1AA: not on the flood risk listCO1 1AG: not on the flood risk listCO1 1AH: not on the flood risk listCO1 1AJ: not on the flood risk listCO1 1AN: not on the flood risk listCO1 1AP: not on the flood risk listCO1 1AQ: not on the flood risk listCO1 1AT: not on the flood risk listCO1 1AU: not on the flood risk listCO1 1AW: not on the flood risk listCO1 1AZ: not on the flood risk listCO1 1BE: not on the flood risk listCO1 1BG: not on the flood risk listCO1 1BQ: not on the flood risk listCO1 1BT: not on the flood risk listCO1 1BX: not on the flood risk listCO1 1BY: not on the flood risk listCO1 1BZ: not on the flood risk listCO1 1DA: not on the flood risk listCO1 1DB: not on the flood risk listCO1 1DF: not on the flood risk listCO1 1DG: not on the flood risk listCO1 1DH: not on the flood risk listCO1 1DJ: not on the flood risk listCO1 1DL: not on the flood risk listCO1 1DN: not on the flood risk listCO1 1DQ: not on the flood risk listCO1 1DS: not on the flood risk listCO1 1DU: not on the flood risk listCO1 1DX: not on the flood risk listCO1 1DZ: not on the flood risk listCO1 1ED: not on the flood risk listCO1 1EE: not on the flood risk listCO1 1EG: not on the flood risk listCO1 1EH: not on the flood risk listCO1 1EJ: not on the flood risk listCO1 1EL: not on the flood risk listCO1 1EN: not on the flood risk listCO1 1EQ: not on the flood risk listCO1 1ES: not on the flood risk listCO1 1EU: not on the flood risk listCO1 1EW: not on the flood risk listCO1 1EY: not on the flood risk listCO1 1EZ: not on the flood risk listCO1 1FA: not on the flood risk listCO1 1FB: not on the flood risk listCO1 1FF: not on the flood risk listCO1 1FQ: not on the flood risk listCO1 1FW: not on the flood risk listCO1 1GJ: not on the flood risk listCO1 1GP: not on the flood risk listCO1 1GX: not on the flood risk listCO1 1GY: not on the flood risk listCO1 1HA: not on the flood risk listCO1 1HB: not on the flood risk listCO1 1HD: not on the flood risk listCO1 1HE: not on the flood risk listCO1 1HF: not on the flood risk listCO1 1HG: not on the flood risk listCO1 1HJ: not on the flood risk listCO1 1HL: not on the flood risk listCO1 1HN: not on the flood risk listCO1 1HP: not on the flood risk listCO1 1HQ: not on the flood risk listCO1 1HR: not on the flood risk listCO1 1HS: not on the flood risk listCO1 1HU: not on the flood risk listCO1 1HW: not on the flood risk listCO1 1HZ: not on the flood risk listCO1 1JB: not on the flood risk listCO1 1JG: not on the flood risk listCO1 1JH: not on the flood risk listCO1 1JJ: not on the flood risk listCO1 1JN: not on the flood risk listCO1 1JQ: not on the flood risk listCO1 1JR: not on the flood risk listCO1 1JT: not on the flood risk listCO1 1JW: not on the flood risk listCO1 1JX: not on the flood risk listCO1 1JZ: not on the flood risk listCO1 1LB: not on the flood risk listCO1 1LD: not on the flood risk listCO1 1LE: not on the flood risk listCO1 1LF: not on the flood risk listCO1 1LG: not on the flood risk listCO1 1LH: not on the flood risk listCO1 1LJ: not on the flood risk listCO1 1LN: not on the flood risk listCO1 1LQ: not on the flood risk listCO1 1LS: not on the flood risk listCO1 1LU: not on the flood risk listCO1 1LX: not on the flood risk listCO1 1LY: not on the flood risk listCO1 1NF: not on the flood risk listCO1 1NG: not on the flood risk listCO1 1NH: not on the flood risk listCO1 1NJ: not on the flood risk listCO1 1NN: not on the flood risk listCO1 1NP: not on the flood risk listCO1 1NQ: not on the flood risk listCO1 1NS: not on the flood risk listCO1 1NT: not on the flood risk listCO1 1NU: not on the flood risk listCO1 1NX: not on the flood risk listCO1 1NY: not on the flood risk listCO1 1NZ: not on the flood risk listCO1 1PA: not on the flood risk listCO1 1PB: not on the flood risk listCO1 1PE: not on the flood risk listCO1 1PG: not on the flood risk listCO1 1PJ: not on the flood risk listCO1 1PN: not on the flood risk listCO1 1PR: not on the flood risk listCO1 1PT: not on the flood risk listCO1 1PW: not on the flood risk listCO1 1PX: not on the flood risk listCO1 1PY: not on the flood risk listCO1 1QP: not on the flood risk listCO1 1QR: not on the flood risk listCO1 1QS: not on the flood risk listCO1 1QW: not on the flood risk listCO1 1QY: not on the flood risk listCO1 1RH: not on the flood risk listCO1 1RN: not on the flood risk listCO1 1RP: not on the flood risk listCO1 1RQ: not on the flood risk listCO1 1RX: not on the flood risk listCO1 1RY: not on the flood risk listCO1 1SB: not on the flood risk listCO1 1SE: not on the flood risk listCO1 1SF: not on the flood risk listCO1 1SG: not on the flood risk listCO1 1SH: not on the flood risk listCO1 1SJ: not on the flood risk listCO1 1SN: not on the flood risk listCO1 1SP: not on the flood risk listCO1 1SQ: not on the flood risk listCO1 1SR: not on the flood risk listCO1 1SS: not on the flood risk listCO1 1ST: not on the flood risk listCO1 1SU: not on the flood risk listCO1 1SZ: not on the flood risk listCO1 1TB: not on the flood risk listCO1 1TD: not on the flood risk listCO1 1TH: not on the flood risk listCO1 1TJ: not on the flood risk listCO1 1TL: not on the flood risk listCO1 1TN: not on the flood risk listCO1 1TP: not on the flood risk listCO1 1TS: not on the flood risk listCO1 1TT: not on the flood risk listCO1 1TW: not on the flood risk listCO1 1TY: not on the flood risk listCO1 1UA: not on the flood risk listCO1 1UB: not on the flood risk listCO1 1UD: not on the flood risk listCO1 1UE: not on the flood risk listCO1 1UF: not on the flood risk listCO1 1UG: not on the flood risk listCO1 1UL: not on the flood risk listCO1 1UN: not on the flood risk listCO1 1UP: not on the flood risk listCO1 1UR: not on the flood risk listCO1 1US: not on the flood risk listCO1 1UT: not on the flood risk listCO1 1UW: not on the flood risk listCO1 1UX: not on the flood risk listCO1 1UZ: not on the flood risk listCO1 1WB: not on the flood risk listCO1 1WD: not on the flood risk listCO1 1WF: not on the flood risk listCO1 1WG: not on the flood risk listCO1 1WJ: not on the flood risk listCO1 1WN: not on the flood risk listCO1 1WQ: not on the flood risk listCO1 1WR: not on the flood risk listCO1 1XA: not on the flood risk listCO1 1XD: not on the flood risk listCO1 1XF: not on the flood risk listCO1 1XJ: not on the flood risk listCO1 1XN: not on the flood risk listCO1 1XP: not on the flood risk listCO1 1XR: not on the flood risk listCO1 1XT: not on the flood risk listCO1 1XW: not on the flood risk listCO1 1XX: not on the flood risk listCO1 1XY: not on the flood risk listCO1 1YA: not on the flood risk listCO1 1YD: not on the flood risk listCO1 1YE: not on the flood risk listCO1 1YF: not on the flood risk listCO1 1YH: not on the flood risk listCO1 1YN: not on the flood risk listCO1 1ZA: not on the flood risk listCO1 1ZR: not on the flood risk listCO1 1ZS: not on the flood risk listCO1 1ZU: not on the flood risk listCO1 1ZX: not on the flood risk listCO1 1ZY: not on the flood risk listCO1 1RB: very low flood risk onlyCO1 1RL: very low flood risk onlyCO1 1EA: low flood risk at worstCO1 1GD: low flood risk at worstCO1 1QE: low flood risk at worstCO1 1QT: low flood risk at worstCO1 1QX: low flood risk at worstCO1 1RA: low flood risk at worstCO1 1RD: low flood risk at worstCO1 1RE: low flood risk at worstCO1 1RJ: low flood risk at worstCO1 1RR: low flood risk at worstCO1 1RT: low flood risk at worstCO1 1RU: low flood risk at worstCO1 1RZ: low flood risk at worstCO1 1SA: low flood risk at worstCO1 1WW: low flood risk at worstCO1 1XS: low flood risk at worstCO1 1ZP: low flood risk at worstCO1 1QD: medium flood risk at worstCO1 1QH: medium flood risk at worstCO1 1RS: medium flood risk at worstCO1 1UU: medium flood risk at worstCO1 1XL: medium flood risk at worstCO1 1QG: high flood riskCO1 1QJ: high flood riskCO1 1XZ: high flood risk Colchester 5 postcodes at high or medium risk, outlined: this goes to CO1 1XZ, the one with most homes and businesses at high risk5 postcodes at high or medium risk Map of every postcode in the CO1 1 sector, by flood risk Of the 234 postcodes in the CO1 1 sector that ONS places, 3 have a home or business at high risk, 5 are at medium risk at worst, 18 are at low risk at worst, 2 are at very low risk only and 206 are not on the Environment Agency's at-risk list. One group of postcodes at high or medium risk is outlined: 5 postcodes at high or medium risk. Places named: Colchester. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 250 m. Colchester
  • A home or business at high risk: 3
  • At medium risk at worst: 5
  • At low risk at worst: 18
  • At very low risk only: 2
  • Not on the at-risk list: 206
  • Outline: where 5 or more postcodes at high or medium risk lie together

Of the 234 postcodes in the CO1 1 sector that ONS places, 3 have a home or business at high risk, 5 are at medium risk at worst, 18 are at low risk at worst, 2 are at very low risk only and 206 are not on the Environment Agency's at-risk list.

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.

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026, the centre point of each postcode; flood risk: Environment Agency, published 6 July 2026; 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 postcodes at high risk

Beside each: how many of its homes and businesses the Environment Agency puts at that risk.

CO1 1XZ8 at high riskCO1 1QG3 at high riskCO1 1QJ1 at high risk

Where the postcodes at high or medium risk lie together

  • 5 postcodes at high or medium risk, outlined on the map. CO1 1XZ, is the one with most homes and businesses at high risk.

What do homes sell for in CO1 1?

Homes in CO1 1 sold for a typical £245,000 in the 12 months to August 2026, across 81 sales, up 1.2% on the 12 months before, HM Land Registry's figures show.

£245,000 typical price, the 12 months to August 2026
£242,000 12 months to August 2025
▲ up 1.2% on the 12 months before
  • Detached £400,000 5 sales
  • Semi-detached £317,500 10 sales
  • Terraced £280,000 28 sales
  • Flat or maisonette £165,000 38 sales

Each bar is that kind's typical price, against the most expensive kind here.

Standard sales of homes at market value at the postcodes that start CO1 1. A typical price is the median, the middle sale, given from 5 sales or more.

How we work this out: house prices by postcode

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

Postcodes in CO1 1

Pick a postcode to see its council and MP, broadband, flood risk, what homes sell for, council tax, the nearest schools and stations, and crime around it.

CO1 1AACO1 1AGCO1 1AHCO1 1AJCO1 1ANCO1 1APCO1 1AQCO1 1ATCO1 1AUCO1 1AWCO1 1AZCO1 1BECO1 1BGCO1 1BQCO1 1BTCO1 1BXCO1 1BYCO1 1BZCO1 1DACO1 1DBCO1 1DFCO1 1DGCO1 1DHCO1 1DJCO1 1DLCO1 1DNCO1 1DQCO1 1DSCO1 1DUCO1 1DXCO1 1DZCO1 1EACO1 1EDCO1 1EECO1 1EGCO1 1EHCO1 1EJCO1 1ELCO1 1ENCO1 1EQCO1 1ESCO1 1EUCO1 1EWCO1 1EYCO1 1EZCO1 1FACO1 1FBCO1 1FFCO1 1FQCO1 1FWCO1 1GDCO1 1GJCO1 1GPCO1 1GQCO1 1GXCO1 1GYCO1 1HACO1 1HBCO1 1HDCO1 1HECO1 1HFCO1 1HGCO1 1HJCO1 1HLCO1 1HNCO1 1HPCO1 1HQCO1 1HRCO1 1HSCO1 1HUCO1 1HWCO1 1HZCO1 1JBCO1 1JGCO1 1JHCO1 1JJCO1 1JNCO1 1JQCO1 1JRCO1 1JSCO1 1JTCO1 1JWCO1 1JXCO1 1JZCO1 1LBCO1 1LDCO1 1LECO1 1LFCO1 1LGCO1 1LHCO1 1LJCO1 1LNCO1 1LQCO1 1LSCO1 1LUCO1 1LXCO1 1LYCO1 1NFCO1 1NGCO1 1NHCO1 1NJCO1 1NNCO1 1NPCO1 1NQCO1 1NSCO1 1NTCO1 1NUCO1 1NXCO1 1NYCO1 1NZCO1 1PACO1 1PBCO1 1PECO1 1PGCO1 1PJCO1 1PNCO1 1PRCO1 1PTCO1 1PWCO1 1PXCO1 1PYCO1 1QDCO1 1QECO1 1QGCO1 1QHCO1 1QJCO1 1QPCO1 1QRCO1 1QSCO1 1QTCO1 1QWCO1 1QXCO1 1QYCO1 1RACO1 1RBCO1 1RDCO1 1RECO1 1RHCO1 1RJCO1 1RLCO1 1RNCO1 1RPCO1 1RQCO1 1RRCO1 1RSCO1 1RTCO1 1RUCO1 1RXCO1 1RYCO1 1RZCO1 1SACO1 1SBCO1 1SECO1 1SFCO1 1SGCO1 1SHCO1 1SJCO1 1SNCO1 1SPCO1 1SQCO1 1SRCO1 1SSCO1 1STCO1 1SUCO1 1SZCO1 1TBCO1 1TDCO1 1TGCO1 1THCO1 1TJCO1 1TLCO1 1TNCO1 1TPCO1 1TSCO1 1TTCO1 1TWCO1 1TYCO1 1UACO1 1UBCO1 1UDCO1 1UECO1 1UFCO1 1UGCO1 1ULCO1 1UNCO1 1UPCO1 1URCO1 1USCO1 1UTCO1 1UUCO1 1UWCO1 1UXCO1 1UZCO1 1WACO1 1WBCO1 1WDCO1 1WECO1 1WFCO1 1WGCO1 1WJCO1 1WNCO1 1WQCO1 1WRCO1 1WWCO1 1XACO1 1XDCO1 1XFCO1 1XJCO1 1XLCO1 1XNCO1 1XPCO1 1XRCO1 1XSCO1 1XTCO1 1XWCO1 1XXCO1 1XYCO1 1XZCO1 1YACO1 1YDCO1 1YECO1 1YFCO1 1YHCO1 1YNCO1 1ZACO1 1ZECO1 1ZHCO1 1ZPCO1 1ZRCO1 1ZSCO1 1ZTCO1 1ZUCO1 1ZXCO1 1ZY

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026. Postcodes that have ended are not listed. See all our data sources

What council am I in? The council, borough or local authority for a postcode, and the county council where there is one. What ward am I in? The ward for a postcode, with its council, constituency and parish.

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