CM1 3 postcode sector in the CM1 district

CM1 3 is a sector of the CM1 district: every postcode that starts CM1 3. It has 225 postcodes in use, 8 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 CM1 3 sector, by flood risk

Map of every postcode in the CM1 3 sector, by flood risk Of the 225 postcodes in the CM1 3 sector that ONS places, 6 have a home or business at high risk, 3 are at medium risk at worst, 2 are at low risk at worst and 214 are not on the Environment Agency's at-risk list. Places named: Chelmsford, Writtle. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2 km. A1114 CM1 3AA: not on the flood risk listCM1 3AE: not on the flood risk listCM1 3AF: not on the flood risk listCM1 3AG: not on the flood risk listCM1 3AR: not on the flood risk listCM1 3AX: not on the flood risk listCM1 3BB: not on the flood risk listCM1 3BH: not on the flood risk listCM1 3BJ: not on the flood risk listCM1 3BL: not on the flood risk listCM1 3BP: not on the flood risk listCM1 3BS: not on the flood risk listCM1 3BT: not on the flood risk listCM1 3BW: not on the flood risk listCM1 3BX: not on the flood risk listCM1 3BY: not on the flood risk listCM1 3BZ: not on the flood risk listCM1 3DB: not on the flood risk listCM1 3DD: not on the flood risk listCM1 3DF: not on the flood risk listCM1 3DG: not on the flood risk listCM1 3DH: not on the flood risk listCM1 3DJ: not on the flood risk listCM1 3DL: not on the flood risk listCM1 3DN: not on the flood risk listCM1 3DP: not on the flood risk listCM1 3DQ: not on the flood risk listCM1 3DR: not on the flood risk listCM1 3DS: not on the flood risk listCM1 3DT: not on the flood risk listCM1 3DU: not on the flood risk listCM1 3DX: not on the flood risk listCM1 3DZ: not on the flood risk listCM1 3EB: not on the flood risk listCM1 3ED: not on the flood risk listCM1 3EE: not on the flood risk listCM1 3EF: not on the flood risk listCM1 3EH: not on the flood risk listCM1 3EJ: not on the flood risk listCM1 3EN: not on the flood risk listCM1 3EP: not on the flood risk listCM1 3EQ: not on the flood risk listCM1 3ES: not on the flood risk listCM1 3EW: not on the flood risk listCM1 3EZ: not on the flood risk listCM1 3FE: not on the flood risk listCM1 3FF: not on the flood risk listCM1 3FH: not on the flood risk listCM1 3FJ: not on the flood risk listCM1 3FL: not on the flood risk listCM1 3FN: not on the flood risk listCM1 3GA: not on the flood risk listCM1 3GD: not on the flood risk listCM1 3GF: not on the flood risk listCM1 3GH: not on the flood risk listCM1 3GJ: not on the flood risk listCM1 3GL: not on the flood risk listCM1 3GN: not on the flood risk listCM1 3GP: not on the flood risk listCM1 3GR: not on the flood risk listCM1 3GS: not on the flood risk listCM1 3GY: not on the flood risk listCM1 3HB: not on the flood risk listCM1 3HD: not on the flood risk listCM1 3HE: not on the flood risk listCM1 3HF: not on the flood risk listCM1 3HG: not on the flood risk listCM1 3HH: not on the flood risk listCM1 3HJ: not on the flood risk listCM1 3HL: not on the flood risk listCM1 3HN: not on the flood risk listCM1 3HP: not on the flood risk listCM1 3HQ: not on the flood risk listCM1 3HT: not on the flood risk listCM1 3HY: not on the flood risk listCM1 3JA: not on the flood risk listCM1 3JB: not on the flood risk listCM1 3JE: not on the flood risk listCM1 3JF: not on the flood risk listCM1 3JG: not on the flood risk listCM1 3JH: not on the flood risk listCM1 3JJ: not on the flood risk listCM1 3JL: not on the flood risk listCM1 3JN: not on the flood risk listCM1 3JP: not on the flood risk listCM1 3JQ: not on the flood risk listCM1 3JS: not on the flood risk listCM1 3JT: not on the flood risk listCM1 3JU: not on the flood risk listCM1 3JY: not on the flood risk listCM1 3JZ: not on the flood risk listCM1 3LE: not on the flood risk listCM1 3LF: not on the flood risk listCM1 3LG: not on the flood risk listCM1 3LH: not on the flood risk listCM1 3LJ: not on the flood risk listCM1 3LN: not on the flood risk listCM1 3LP: not on the flood risk listCM1 3LS: not on the flood risk listCM1 3LT: not on the flood risk listCM1 3LW: not on the flood risk listCM1 3LY: not on the flood risk listCM1 3NA: not on the flood risk listCM1 3NB: not on the flood risk listCM1 3ND: not on the flood risk listCM1 3NF: not on the flood risk listCM1 3NH: not on the flood risk listCM1 3NJ: not on the flood risk listCM1 3NN: not on the flood risk listCM1 3NP: not on the flood risk listCM1 3NQ: not on the flood risk listCM1 3NR: not on the flood risk listCM1 3NT: not on the flood risk listCM1 3NU: not on the flood risk listCM1 3NW: not on the flood risk listCM1 3NX: not on the flood risk listCM1 3NY: not on the flood risk listCM1 3NZ: not on the flood risk listCM1 3PA: not on the flood risk listCM1 3PB: not on the flood risk listCM1 3PD: not on the flood risk listCM1 3PE: not on the flood risk listCM1 3PF: not on the flood risk listCM1 3PH: not on the flood risk listCM1 3PJ: not on the flood risk listCM1 3PN: not on the flood risk listCM1 3PQ: not on the flood risk listCM1 3PR: not on the flood risk listCM1 3PS: not on the flood risk listCM1 3PU: not on the flood risk listCM1 3PX: not on the flood risk listCM1 3PZ: not on the flood risk listCM1 3QD: not on the flood risk listCM1 3QE: not on the flood risk listCM1 3QF: not on the flood risk listCM1 3QG: not on the flood risk listCM1 3QH: not on the flood risk listCM1 3QJ: not on the flood risk listCM1 3QL: not on the flood risk listCM1 3QP: not on the flood risk listCM1 3QR: not on the flood risk listCM1 3QS: not on the flood risk listCM1 3QT: not on the flood risk listCM1 3QU: not on the flood risk listCM1 3QW: not on the flood risk listCM1 3QY: not on the flood risk listCM1 3QZ: not on the flood risk listCM1 3RA: not on the flood risk listCM1 3RB: not on the flood risk listCM1 3RD: not on the flood risk listCM1 3RE: not on the flood risk listCM1 3RF: not on the flood risk listCM1 3RG: not on the flood risk listCM1 3RH: not on the flood risk listCM1 3RP: not on the flood risk listCM1 3RS: not on the flood risk listCM1 3RT: not on the flood risk listCM1 3RU: not on the flood risk listCM1 3RY: not on the flood risk listCM1 3SB: not on the flood risk listCM1 3SD: not on the flood risk listCM1 3SE: not on the flood risk listCM1 3SF: not on the flood risk listCM1 3SG: not on the flood risk listCM1 3SH: not on the flood risk listCM1 3SJ: not on the flood risk listCM1 3SL: not on the flood risk listCM1 3SN: not on the flood risk listCM1 3SP: not on the flood risk listCM1 3SQ: not on the flood risk listCM1 3SR: not on the flood risk listCM1 3SS: not on the flood risk listCM1 3SX: not on the flood risk listCM1 3SY: not on the flood risk listCM1 3TF: not on the flood risk listCM1 3TH: not on the flood risk listCM1 3UB: not on the flood risk listCM1 3WR: not on the flood risk listCM1 3WS: not on the flood risk listCM1 3WT: not on the flood risk listCM1 3YA: not on the flood risk listCM1 3EU: low flood risk at worstCM1 3SU: low flood risk at worstCM1 3EA: medium flood risk at worstCM1 3EY: medium flood risk at worstCM1 3RR: medium flood risk at worstCM1 3ET: high flood riskCM1 3EX: high flood riskCM1 3RL: high flood riskCM1 3RN: high flood riskCM1 3RZ: high flood riskCM1 3SA: high flood risk ChelmsfordWrittle Map of every postcode in the CM1 3 sector, by flood risk Of the 225 postcodes in the CM1 3 sector that ONS places, 6 have a home or business at high risk, 3 are at medium risk at worst, 2 are at low risk at worst and 214 are not on the Environment Agency's at-risk list. Places named: Chelmsford, Writtle. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. A12 ChelmsfordWrittle
  • A home or business at high risk: 6
  • At medium risk at worst: 3
  • At low risk at worst: 2
  • At very low risk only: 0
  • Not on the at-risk list: 214

Of the 225 postcodes in the CM1 3 sector that ONS places, 6 have a home or business at high risk, 3 are at medium risk at worst, 2 are at low risk at worst and 214 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. 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.

CM1 3SA13 at high riskCM1 3RZ4 at high riskCM1 3EX3 at high riskCM1 3RL3 at high riskCM1 3RN3 at high riskCM1 3ET1 at high risk

What do homes sell for in CM1 3?

Homes in CM1 3 sold for a typical £465,000 in the 12 months to August 2026, across 71 sales, up 9.4% on the 12 months before, HM Land Registry's figures show.

£465,000 typical price, the 12 months to August 2026
£425,000 12 months to August 2025
▲ up 9.4% on the 12 months before
  • Detached £590,000 19 sales
  • Semi-detached £475,000 25 sales
  • Terraced £410,000 13 sales
  • Flat or maisonette £203,750 14 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 CM1 3. 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 CM1 3

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.

CM1 3AACM1 3AECM1 3AFCM1 3AGCM1 3ARCM1 3ATCM1 3AXCM1 3BBCM1 3BHCM1 3BJCM1 3BLCM1 3BPCM1 3BSCM1 3BTCM1 3BUCM1 3BWCM1 3BXCM1 3BYCM1 3BZCM1 3DACM1 3DBCM1 3DDCM1 3DECM1 3DFCM1 3DGCM1 3DHCM1 3DJCM1 3DLCM1 3DNCM1 3DPCM1 3DQCM1 3DRCM1 3DSCM1 3DTCM1 3DUCM1 3DXCM1 3DYCM1 3DZCM1 3EACM1 3EBCM1 3EDCM1 3EECM1 3EFCM1 3EGCM1 3EHCM1 3EJCM1 3ELCM1 3ENCM1 3EPCM1 3EQCM1 3ESCM1 3ETCM1 3EUCM1 3EWCM1 3EXCM1 3EYCM1 3EZCM1 3FDCM1 3FECM1 3FFCM1 3FHCM1 3FJCM1 3FLCM1 3FNCM1 3GACM1 3GDCM1 3GFCM1 3GGCM1 3GHCM1 3GJCM1 3GLCM1 3GNCM1 3GPCM1 3GRCM1 3GSCM1 3GUCM1 3GWCM1 3GYCM1 3GZCM1 3HBCM1 3HDCM1 3HECM1 3HFCM1 3HGCM1 3HHCM1 3HJCM1 3HLCM1 3HNCM1 3HPCM1 3HQCM1 3HRCM1 3HSCM1 3HTCM1 3HWCM1 3HYCM1 3HZCM1 3JACM1 3JBCM1 3JDCM1 3JECM1 3JFCM1 3JGCM1 3JHCM1 3JJCM1 3JLCM1 3JNCM1 3JPCM1 3JQCM1 3JRCM1 3JSCM1 3JTCM1 3JUCM1 3JWCM1 3JXCM1 3JYCM1 3JZCM1 3LECM1 3LFCM1 3LGCM1 3LHCM1 3LJCM1 3LLCM1 3LNCM1 3LPCM1 3LQCM1 3LRCM1 3LSCM1 3LTCM1 3LWCM1 3LYCM1 3NACM1 3NBCM1 3NDCM1 3NECM1 3NFCM1 3NGCM1 3NHCM1 3NJCM1 3NLCM1 3NNCM1 3NPCM1 3NQCM1 3NRCM1 3NSCM1 3NTCM1 3NUCM1 3NWCM1 3NXCM1 3NYCM1 3NZCM1 3PACM1 3PBCM1 3PDCM1 3PECM1 3PFCM1 3PHCM1 3PJCM1 3PNCM1 3PQCM1 3PRCM1 3PSCM1 3PUCM1 3PWCM1 3PXCM1 3PZCM1 3QDCM1 3QECM1 3QFCM1 3QGCM1 3QHCM1 3QJCM1 3QLCM1 3QPCM1 3QRCM1 3QSCM1 3QTCM1 3QUCM1 3QWCM1 3QYCM1 3QZCM1 3RACM1 3RBCM1 3RDCM1 3RECM1 3RFCM1 3RGCM1 3RHCM1 3RLCM1 3RNCM1 3RPCM1 3RQCM1 3RRCM1 3RSCM1 3RTCM1 3RUCM1 3RWCM1 3RYCM1 3RZCM1 3SACM1 3SBCM1 3SDCM1 3SECM1 3SFCM1 3SGCM1 3SHCM1 3SJCM1 3SLCM1 3SNCM1 3SPCM1 3SQCM1 3SRCM1 3SSCM1 3STCM1 3SUCM1 3SXCM1 3SYCM1 3TFCM1 3THCM1 3UBCM1 3USCM1 3WQCM1 3WRCM1 3WSCM1 3WTCM1 3YA

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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