CM20 postcode district: Harlow and around

CM20 is a postcode district mostly in Essex, with 629 postcodes in use in 4 sectors. It has postcodes in Harlow. It is split between 2 councils: Harlow (597 postcodes) and East Hertfordshire (32). 597 are in Essex and 32 in Hertfordshire.

Postcodes in use
629
Sectors
4
Councils
2 councils
Places
Harlow

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026. See all our data sources

Every postcode in CM20, by flood risk

Map of every postcode in CM20, by flood risk Of the 629 postcodes in CM20 that ONS places, 11 have a home or business at high risk, 4 are at medium risk at worst, 8 are at low risk at worst and 606 are not on the Environment Agency's at-risk list. 3 postcodes lie beyond the edge and are listed under the map. Places named: Harlow. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 500 m. CM20 1AA: not on the flood risk listCM20 1AB: not on the flood risk listCM20 1AJ: not on the flood risk listCM20 1AN: not on the flood risk listCM20 1AR: not on the flood risk listCM20 1AS: not on the flood risk listCM20 1AT: not on the flood risk listCM20 1AU: not on the flood risk listCM20 1AW: not on the flood risk listCM20 1AY: not on the flood risk listCM20 1BA: not on the flood risk listCM20 1BL: not on the flood risk listCM20 1BU: not on the flood risk listCM20 1BW: not on the flood risk listCM20 1BX: not on the flood risk listCM20 1BZ: not on the flood risk listCM20 1DG: not on the flood risk listCM20 1DR: not on the flood risk listCM20 1DS: not on the flood risk listCM20 1DT: not on the flood risk listCM20 1DU: not on the flood risk listCM20 1DZ: not on the flood risk listCM20 1EA: not on the flood risk listCM20 1EB: not on the flood risk listCM20 1ED: not on the flood risk listCM20 1EE: not on the flood risk listCM20 1EF: not on the flood risk listCM20 1EG: not on the flood risk listCM20 1EJ: not on the flood risk listCM20 1EL: not on the flood risk listCM20 1EN: not on the flood risk listCM20 1EP: not on the flood risk listCM20 1ES: not on the flood risk listCM20 1EY: not on the flood risk listCM20 1FA: not on the flood risk listCM20 1FD: not on the flood risk listCM20 1FE: not on the flood risk listCM20 1FH: not on the flood risk listCM20 1FJ: not on the flood risk listCM20 1FL: not on the flood risk listCM20 1FS: not on the flood risk listCM20 1FT: not on the flood risk listCM20 1FU: not on the flood risk listCM20 1FW: not on the flood risk listCM20 1HA: not on the flood risk listCM20 1HF: not on the flood risk listCM20 1HG: not on the flood risk listCM20 1HP: not on the flood risk listCM20 1HX: not on the flood risk listCM20 1JA: not on the flood risk listCM20 1JF: not on the flood risk listCM20 1JG: not on the flood risk listCM20 1JH: not on the flood risk listCM20 1JJ: not on the flood risk listCM20 1JL: not on the flood risk listCM20 1JN: not on the flood risk listCM20 1JQ: not on the flood risk listCM20 1LP: not on the flood risk listCM20 1LS: not on the flood risk listCM20 1NA: not on the flood risk listCM20 1NB: not on the flood risk listCM20 1NL: not on the flood risk listCM20 1NN: not on the flood risk listCM20 1NP: not on the flood risk listCM20 1NR: not on the flood risk listCM20 1NS: not on the flood risk listCM20 1NT: not on the flood risk listCM20 1NU: not on the flood risk listCM20 1NW: not on the flood risk listCM20 1NX: not on the flood risk listCM20 1NY: not on the flood risk listCM20 1NZ: not on the flood risk listCM20 1PA: not on the flood risk listCM20 1PB: not on the flood risk listCM20 1PD: not on the flood risk listCM20 1PE: not on the flood risk listCM20 1PG: not on the flood risk listCM20 1PH: not on the flood risk listCM20 1PJ: not on the flood risk listCM20 1PL: not on the flood risk listCM20 1PN: not on the flood risk listCM20 1PP: not on the flood risk listCM20 1PQ: not on the flood risk listCM20 1PR: not on the flood risk listCM20 1PU: not on the flood risk listCM20 1PW: not on the flood risk listCM20 1PX: not on the flood risk listCM20 1PY: not on the flood risk listCM20 1PZ: not on the flood risk listCM20 1QA: not on the flood risk listCM20 1QB: not on the flood risk listCM20 1QD: not on the flood risk listCM20 1QE: not on the flood risk listCM20 1QF: not on the flood risk listCM20 1QG: not on the flood risk listCM20 1QP: not on the flood risk listCM20 1QQ: not on the flood risk listCM20 1QR: not on the flood risk listCM20 1QX: not on the flood risk listCM20 1RD: not on the flood risk listCM20 1RE: not on the flood risk listCM20 1RF: not on the flood risk listCM20 1RG: not on the flood risk listCM20 1RJ: not on the flood risk listCM20 1RL: not on the flood risk listCM20 1RN: not on the flood risk listCM20 1RP: not on the flood risk listCM20 1RQ: not on the flood risk listCM20 1RR: not on the flood risk listCM20 1RS: not on the flood risk listCM20 1RT: not on the flood risk listCM20 1RU: not on the flood risk listCM20 1RW: not on the flood risk listCM20 1SB: not on the flood risk listCM20 1SD: not on the flood risk listCM20 1SE: not on the flood risk listCM20 1SF: not on the flood risk listCM20 1SG: not on the flood risk listCM20 1SH: not on the flood risk listCM20 1SJ: not on the flood risk listCM20 1SL: not on the flood risk listCM20 1SN: not on the flood risk listCM20 1SP: not on the flood risk listCM20 1SQ: not on the flood risk listCM20 1SU: not on the flood risk listCM20 1SW: not on the flood risk listCM20 1SX: not on the flood risk listCM20 1SY: not on the flood risk listCM20 1SZ: not on the flood risk listCM20 1TA: not on the flood risk listCM20 1TB: not on the flood risk listCM20 1TD: not on the flood risk listCM20 1TE: not on the flood risk listCM20 1TH: not on the flood risk listCM20 1TJ: not on the flood risk listCM20 1TL: not on the flood risk listCM20 1TN: not on the flood risk listCM20 1TP: not on the flood risk listCM20 1TQ: not on the flood risk listCM20 1TW: not on the flood risk listCM20 1WG: not on the flood risk listCM20 1XA: not on the flood risk listCM20 1XN: not on the flood risk listCM20 1XP: not on the flood risk listCM20 1XR: not on the flood risk listCM20 1XW: not on the flood risk listCM20 1YU: not on the flood risk listCM20 2AA: not on the flood risk listCM20 2AB: not on the flood risk listCM20 2AG: not on the flood risk listCM20 2AN: not on the flood risk listCM20 2AP: not on the flood risk listCM20 2AR: not on the flood risk listCM20 2AS: not on the flood risk listCM20 2BD: not on the flood risk listCM20 2BG: not on the flood risk listCM20 2BH: not on the flood risk listCM20 2BJ: not on the flood risk listCM20 2BL: not on the flood risk listCM20 2BN: not on the flood risk listCM20 2BQ: not on the flood risk listCM20 2BS: not on the flood risk listCM20 2BT: not on the flood risk listCM20 2BU: not on the flood risk listCM20 2BX: not on the flood risk listCM20 2BZ: not on the flood risk listCM20 2DA: not on the flood risk listCM20 2DB: not on the flood risk listCM20 2DG: not on the flood risk listCM20 2DH: not on the flood risk listCM20 2DJ: not on the flood risk listCM20 2DP: not on the flood risk listCM20 2DQ: not on the flood risk listCM20 2DR: not on the flood risk listCM20 2DS: not on the flood risk listCM20 2DU: not on the flood risk listCM20 2DY: not on the flood risk listCM20 2EA: not on the flood risk listCM20 2ED: not on the flood risk listCM20 2EG: not on the flood risk listCM20 2EL: not on the flood risk listCM20 2EQ: not on the flood risk listCM20 2ET: not on the flood risk listCM20 2EU: not on the flood risk listCM20 2EY: not on the flood risk listCM20 2FB: not on the flood risk listCM20 2FD: not on the flood risk listCM20 2FF: not on the flood risk listCM20 2FG: not on the flood risk listCM20 2FH: not on the flood risk listCM20 2FL: not on the flood risk listCM20 2FN: not on the flood risk listCM20 2FP: not on the flood risk listCM20 2FR: not on the flood risk listCM20 2FT: not on the flood risk listCM20 2FU: not on the flood risk listCM20 2FW: not on the flood risk listCM20 2FX: not on the flood risk listCM20 2FY: not on the flood risk listCM20 2FZ: not on the flood risk listCM20 2GB: not on the flood risk listCM20 2GD: not on the flood risk listCM20 2GF: not on the flood risk listCM20 2GJ: not on the flood risk listCM20 2GL: not on the flood risk listCM20 2GN: not on the flood risk listCM20 2GQ: not on the flood risk listCM20 2GS: not on the flood risk listCM20 2GU: not on the flood risk listCM20 2GW: not on the flood risk listCM20 2GY: not on the flood risk listCM20 2HJ: not on the flood risk listCM20 2HR: not on the flood risk listCM20 2HS: not on the flood risk listCM20 2HT: not on the flood risk listCM20 2HU: not on the flood risk listCM20 2HW: not on the flood risk listCM20 2JA: not on the flood risk listCM20 2JB: not on the flood risk listCM20 2JD: not on the flood risk listCM20 2JP: not on the flood risk listCM20 2JR: not on the flood risk listCM20 2JS: not on the flood risk listCM20 2JT: not on the flood risk listCM20 2JU: not on the flood risk listCM20 2JX: not on the flood risk listCM20 2JY: not on the flood risk listCM20 2JZ: not on the flood risk listCM20 2LA: not on the flood risk listCM20 2LB: not on the flood risk listCM20 2LD: not on the flood risk listCM20 2LE: not on the flood risk listCM20 2LF: not on the flood risk listCM20 2LG: not on the flood risk listCM20 2LH: not on the flood risk listCM20 2LJ: not on the flood risk listCM20 2LL: not on the flood risk listCM20 2LN: not on the flood risk listCM20 2LP: not on the flood risk listCM20 2LQ: not on the flood risk listCM20 2LR: not on the flood risk listCM20 2LS: not on the flood risk listCM20 2LT: not on the flood risk listCM20 2LU: not on the flood risk listCM20 2LW: not on the flood risk listCM20 2LX: not on the flood risk listCM20 2LY: not on the flood risk listCM20 2LZ: not on the flood risk listCM20 2NA: not on the flood risk listCM20 2NB: not on the flood risk listCM20 2ND: not on the flood risk listCM20 2NE: not on the flood risk listCM20 2NF: not on the flood risk listCM20 2NG: not on the flood risk listCM20 2NP: not on the flood risk listCM20 2NQ: not on the flood risk listCM20 2NR: not on the flood risk listCM20 2NS: not on the flood risk listCM20 2NT: not on the flood risk listCM20 2NU: not on the flood risk listCM20 2NW: not on the flood risk listCM20 2NX: not on the flood risk listCM20 2NY: not on the flood risk listCM20 2PA: not on the flood risk listCM20 2PB: not on the flood risk listCM20 2PD: not on the flood risk listCM20 2PE: not on the flood risk listCM20 2PF: not on the flood risk listCM20 2PG: not on the flood risk listCM20 2PH: not on the flood risk listCM20 2PJ: not on the flood risk listCM20 2PL: not on the flood risk listCM20 2PN: not on the flood risk listCM20 2PQ: not on the flood risk listCM20 2PR: not on the flood risk listCM20 2PW: not on the flood risk listCM20 2PX: not on the flood risk listCM20 2PY: not on the flood risk listCM20 2PZ: not on the flood risk listCM20 2QB: not on the flood risk listCM20 2QD: not on the flood risk listCM20 2QE: not on the flood risk listCM20 2QF: not on the flood risk listCM20 2QG: not on the flood risk listCM20 2QH: not on the flood risk listCM20 2QJ: not on the flood risk listCM20 2QL: not on the flood risk listCM20 2QN: not on the flood risk listCM20 2QP: not on the flood risk listCM20 2QQ: not on the flood risk listCM20 2QT: not on the flood risk listCM20 2QU: not on the flood risk listCM20 2QW: not on the flood risk listCM20 2RB: not on the flood risk listCM20 2RD: not on the flood risk listCM20 2RH: not on the flood risk listCM20 2RL: not on the flood risk listCM20 2RN: not on the flood risk listCM20 2RW: not on the flood risk listCM20 2SD: not on the flood risk listCM20 2SF: not on the flood risk listCM20 2SL: not on the flood risk listCM20 2SN: not on the flood risk listCM20 2ST: not on the flood risk listCM20 2SU: not on the flood risk listCM20 2SW: not on the flood risk listCM20 2SX: not on the flood risk listCM20 2SY: not on the flood risk listCM20 2TD: not on the flood risk listCM20 2TG: not on the flood risk listCM20 2TH: not on the flood risk listCM20 2TL: not on the flood risk listCM20 2TN: not on the flood risk listCM20 2TT: not on the flood risk listCM20 2TZ: not on the flood risk listCM20 2UA: not on the flood risk listCM20 2UD: not on the flood risk listCM20 2UJ: not on the flood risk listCM20 2UP: not on the flood risk listCM20 3AB: not on the flood risk listCM20 3AF: not on the flood risk listCM20 3AG: not on the flood risk listCM20 3AH: not on the flood risk listCM20 3AN: not on the flood risk listCM20 3AP: not on the flood risk listCM20 3AQ: not on the flood risk listCM20 3AS: not on the flood risk listCM20 3AX: not on the flood risk listCM20 3BA: not on the flood risk listCM20 3BB: not on the flood risk listCM20 3BD: not on the flood risk listCM20 3BE: not on the flood risk listCM20 3BG: not on the flood risk listCM20 3BH: not on the flood risk listCM20 3BJ: not on the flood risk listCM20 3BL: not on the flood risk listCM20 3BN: not on the flood risk listCM20 3BQ: not on the flood risk listCM20 3BS: not on the flood risk listCM20 3BW: not on the flood risk listCM20 3BY: not on the flood risk listCM20 3DA: not on the flood risk listCM20 3DB: not on the flood risk listCM20 3DD: not on the flood risk listCM20 3DE: not on the flood risk listCM20 3DF: not on the flood risk listCM20 3DG: not on the flood risk listCM20 3DH: not on the flood risk listCM20 3DJ: not on the flood risk listCM20 3DL: not on the flood risk listCM20 3DN: not on the flood risk listCM20 3DP: not on the flood risk listCM20 3DR: not on the flood risk listCM20 3DT: not on the flood risk listCM20 3DU: not on the flood risk listCM20 3DW: not on the flood risk listCM20 3DY: not on the flood risk listCM20 3DZ: not on the flood risk listCM20 3EA: not on the flood risk listCM20 3EB: not on the flood risk listCM20 3ED: not on the flood risk listCM20 3EE: not on the flood risk listCM20 3EF: not on the flood risk listCM20 3EG: not on the flood risk listCM20 3EH: not on the flood risk listCM20 3EJ: not on the flood risk listCM20 3EL: not on the flood risk listCM20 3EN: not on the flood risk listCM20 3EP: not on the flood risk listCM20 3ER: not on the flood risk listCM20 3ES: not on the flood risk listCM20 3ET: not on the flood risk listCM20 3EU: not on the flood risk listCM20 3EW: not on the flood risk listCM20 3EX: not on the flood risk listCM20 3EY: not on the flood risk listCM20 3EZ: not on the flood risk listCM20 3FA: not on the flood risk listCM20 3FB: not on the flood risk listCM20 3FF: not on the flood risk listCM20 3GA: not on the flood risk listCM20 3GN: not on the flood risk listCM20 3GQ: not on the flood risk listCM20 3HB: not on the flood risk listCM20 3HD: not on the flood risk listCM20 3HE: not on the flood risk listCM20 3HF: not on the flood risk listCM20 3HG: not on the flood risk listCM20 3HH: not on the flood risk listCM20 3HJ: not on the flood risk listCM20 3HL: not on the flood risk listCM20 3HN: not on the flood risk listCM20 3HP: not on the flood risk listCM20 3HQ: not on the flood risk listCM20 3HR: not on the flood risk listCM20 3HS: not on the flood risk listCM20 3HT: not on the flood risk listCM20 3HU: not on the flood risk listCM20 3HX: not on the flood risk listCM20 3HY: not on the flood risk listCM20 3HZ: not on the flood risk listCM20 3JA: not on the flood risk listCM20 3JB: not on the flood risk listCM20 3JD: not on the flood risk listCM20 3JE: not on the flood risk listCM20 3JF: not on the flood risk listCM20 3JH: not on the flood risk listCM20 3JJ: not on the flood risk listCM20 3JL: not on the flood risk listCM20 3JN: not on the flood risk listCM20 3JP: not on the flood risk listCM20 3JR: not on the flood risk listCM20 3JS: not on the flood risk listCM20 3JT: not on the flood risk listCM20 3JU: not on the flood risk listCM20 3JW: not on the flood risk listCM20 3JX: not on the flood risk listCM20 3JY: not on the flood risk listCM20 3LA: not on the flood risk listCM20 3LB: not on the flood risk listCM20 3LD: not on the flood risk listCM20 3LE: not on the flood risk listCM20 3LG: not on the flood risk listCM20 3LH: not on the flood risk listCM20 3LJ: not on the flood risk listCM20 3LL: not on the flood risk listCM20 3LN: not on the flood risk listCM20 3LP: not on the flood risk listCM20 3LR: not on the flood risk listCM20 3LS: not on the flood risk listCM20 3LT: not on the flood risk listCM20 3LU: not on the flood risk listCM20 3LW: not on the flood risk listCM20 3LX: not on the flood risk listCM20 3LY: not on the flood risk listCM20 3LZ: not on the flood risk listCM20 3NA: not on the flood risk listCM20 3NB: not on the flood risk listCM20 3ND: not on the flood risk listCM20 3NE: not on the flood risk listCM20 3NG: not on the flood risk listCM20 3NH: not on the flood risk listCM20 3NJ: not on the flood risk listCM20 3NL: not on the flood risk listCM20 3NN: not on the flood risk listCM20 3NP: not on the flood risk listCM20 3NR: not on the flood risk listCM20 3NT: not on the flood risk listCM20 3NU: not on the flood risk listCM20 3NW: not on the flood risk listCM20 3NX: not on the flood risk listCM20 3PA: not on the flood risk listCM20 3PB: not on the flood risk listCM20 3PD: not on the flood risk listCM20 3PE: not on the flood risk listCM20 3PF: not on the flood risk listCM20 3PG: not on the flood risk listCM20 3PH: not on the flood risk listCM20 3PJ: not on the flood risk listCM20 3PL: not on the flood risk listCM20 3PN: not on the flood risk listCM20 3PP: not on the flood risk listCM20 3PQ: not on the flood risk listCM20 3PR: not on the flood risk listCM20 3PS: not on the flood risk listCM20 3PT: not on the flood risk listCM20 3PU: not on the flood risk listCM20 3PX: not on the flood risk listCM20 3PY: not on the flood risk listCM20 3QA: not on the flood risk listCM20 3QB: not on the flood risk listCM20 3QD: not on the flood risk listCM20 3QE: not on the flood risk listCM20 3QF: not on the flood risk listCM20 3QG: not on the flood risk listCM20 3QH: not on the flood risk listCM20 3QJ: not on the flood risk listCM20 3QL: not on the flood risk listCM20 3QN: not on the flood risk listCM20 3QP: not on the flood risk listCM20 3QR: not on the flood risk listCM20 3QS: not on the flood risk listCM20 3QT: not on the flood risk listCM20 3QU: not on the flood risk listCM20 3QW: not on the flood risk listCM20 3QX: not on the flood risk listCM20 3QY: not on the flood risk listCM20 3RA: not on the flood risk listCM20 3RB: not on the flood risk listCM20 3RD: not on the flood risk listCM20 3RE: not on the flood risk listCM20 3RF: not on the flood risk listCM20 3RG: not on the flood risk listCM20 3RH: not on the flood risk listCM20 3RL: not on the flood risk listCM20 3RN: not on the flood risk listCM20 3RP: not on the flood risk listCM20 3RQ: not on the flood risk listCM20 3RR: not on the flood risk listCM20 3RS: not on the flood risk listCM20 3RT: not on the flood risk listCM20 3RU: not on the flood risk listCM20 3RW: not on the flood risk listCM20 3RX: not on the flood risk listCM20 3RY: not on the flood risk listCM20 3RZ: not on the flood risk listCM20 3SA: not on the flood risk listCM20 3SX: not on the flood risk listCM20 3SY: not on the flood risk listCM20 3SZ: not on the flood risk listCM20 9SA: not on the flood risk listCM20 2AD: low flood risk at worstCM20 2ES: low flood risk at worstCM20 2HP: low flood risk at worstCM20 2QZ: low flood risk at worstCM20 2RJ: low flood risk at worstCM20 2RP: low flood risk at worstCM20 2UH: low flood risk at worstCM20 2QY: medium flood risk at worstCM20 2RF: medium flood risk at worstCM20 2UE: medium flood risk at worstCM20 1SR: high flood riskCM20 2DL: high flood riskCM20 2DW: high flood riskCM20 2EP: high flood riskCM20 2HE: high flood riskCM20 2PS: high flood riskCM20 2QS: high flood riskCM20 2QX: high flood riskCM20 2RG: high flood riskCM20 2SE: high flood riskCM20 2UB: high flood risk Harlow Map of every postcode in CM20, by flood risk Of the 629 postcodes in CM20 that ONS places, 11 have a home or business at high risk, 4 are at medium risk at worst, 8 are at low risk at worst and 606 are not on the Environment Agency's at-risk list. 3 postcodes lie beyond the edge and are listed under the map. Places named: Harlow. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 1 km. Harlow
  • A home or business at high risk: 11
  • At medium risk at worst: 4
  • At low risk at worst: 8
  • At very low risk only: 0
  • Not on the at-risk list: 606

Of the 629 postcodes in CM20 that ONS places, 11 have a home or business at high risk, 4 are at medium risk at worst, 8 are at low risk at worst and 606 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.

The middle of its postcodes: latitude 51.7757, longitude 0.1028. Open this area on OpenStreetMap

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.

CM20 2HE12 at high riskCM20 2DL6 at high riskCM20 2QS4 at high riskCM20 2DW3 at high riskCM20 2EP2 at high riskCM20 2UB2 at high riskCM20 2QX1 at high riskCM20 1SR1 at high riskCM20 2PS1 at high riskCM20 2RG1 at high riskCM20 2SE1 at high risk

3 further out, not drawn

These postcodes lie well apart from the rest, so the map is drawn without them to show the rest closer; they are in every count.

CM20 2RACM20 3SDCM20 9SB

What broadband can you get in CM20?

Ofcom reports on 546 of the 629 postcodes in CM20. At 310 of them every home and business can get gigabit broadband, and at 1 some cannot get decent broadband (10 Mbit/s).

Postcodes where every home can get gigabit310 of 546
Postcodes where every home can get superfast457 of 546
Postcodes where some cannot get decent broadband1 of 546

Ofcom gives each postcode's share of homes and businesses, not how many there are, so these count postcodes. Each postcode page has its own figures. A provider's checker answers for one address.

Check one address on Ofcom's checker

Source: Ofcom, Connected Nations, Spring 2026, data for January 2026, Open Government Licence v3.0. How we use it

Is CM20 at risk of flooding?

23 of the 629 postcodes in CM20 have a home or business in an area at risk of flooding from rivers or the sea, the Environment Agency says. At those, it puts 124 homes and businesses in an area at high or medium risk.

Homes and businesses in an area at risk, at 23 of 629 postcodes High: 34Medium: 90Low: 170Very low: 2

High: 3.3% or more a year (1 in 30). Medium: 1% to 3.3% a year. Low: 0.1% to 1% a year. Very low: under 0.1% a year (1 in 1,000). Each band is the chance of flooding in any one year.

Homes and businesses in an area at risk of flooding from rivers or the sea, as the Environment Agency counts them, added up over the postcodes. It is for the land, not each building, and leaves out surface water, groundwater and sewers. Each postcode page has its own figures and its flood warning areas.

Source: Environment Agency, Risk of Flooding from Rivers and Sea (postcodes in areas at risk), published 6 July 2026, Open Government Licence v3.0. How we use it

What do homes sell for in CM20?

Homes in CM20 sold for a typical £325,000 in the 12 months to August 2026, across 195 sales, up 4.8% on the 12 months before, HM Land Registry's figures show.

£325,000 typical price, the 12 months to August 2026
12 months to August 2025
£310,000
12 months to August 2026
£325,000

▲ up 4.8% on the 12 months before

Detached£636,000 10 sales
Semi-detached£400,000 15 sales
Terraced£335,000 99 sales
Flat or maisonette£202,000 71 sales

Standard sales of homes at market value. A typical price is the median, the middle sale. Sales take weeks to be registered, so the last month or two are incomplete. Each postcode page gives the figure for its own postcode sector.

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 CM20

Pick a sector, then a postcode. A sector is the district plus the next digit.

CM20 1161 postcodesCM20 2204 postcodesCM20 3195 postcodesCM20 969 postcodes
UK postcode format explained

Places in CM20

Towns and villages with postcodes in CM20, and how many each has here.

Harlow postcodes,609

Who covers CM20

How many of the district's postcodes in use fall under each council, constituency and police force area.

Councils

What council am I in?

Constituencies

  • Harlow597
  • Hertford and Stortford32

Police force areas

  • Essex597
  • Hertfordshire32

Next to CM20

CM19 postcode district CM21 postcode district All CM districts Harlow postcodes

"Next to" is by number: the districts before and after CM20 in the CM area.

Check a postcode

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