S21 1 postcode sector in the S21 district

S21 1 is a sector of the S21 district: every postcode that starts S21 1. It has 187 postcodes in use, one of them a large-user postcode. 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 S21 1 sector, by flood risk

Map of every postcode in the S21 1 sector, by flood risk Of the 187 postcodes in the S21 1 sector that ONS places, 4 have a home or business at high risk, 3 are at medium risk at worst, 3 are at low risk at worst, 11 are at very low risk only and 166 are not on the Environment Agency's at-risk list. One postcode lies beyond the edge and is listed under the map. Places named: Killamarsh. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 250 m. S21 1AA: not on the flood risk listS21 1AB: not on the flood risk listS21 1AD: not on the flood risk listS21 1AE: not on the flood risk listS21 1AF: not on the flood risk listS21 1AG: not on the flood risk listS21 1AH: not on the flood risk listS21 1AL: not on the flood risk listS21 1AN: not on the flood risk listS21 1AP: not on the flood risk listS21 1AQ: not on the flood risk listS21 1AR: not on the flood risk listS21 1AT: not on the flood risk listS21 1AW: not on the flood risk listS21 1AX: not on the flood risk listS21 1AY: not on the flood risk listS21 1AZ: not on the flood risk listS21 1BA: not on the flood risk listS21 1BB: not on the flood risk listS21 1BD: not on the flood risk listS21 1BE: not on the flood risk listS21 1BF: not on the flood risk listS21 1BG: not on the flood risk listS21 1BH: not on the flood risk listS21 1BJ: not on the flood risk listS21 1BL: not on the flood risk listS21 1BN: not on the flood risk listS21 1BP: not on the flood risk listS21 1BR: not on the flood risk listS21 1BS: not on the flood risk listS21 1BT: not on the flood risk listS21 1BU: not on the flood risk listS21 1BW: not on the flood risk listS21 1BX: not on the flood risk listS21 1BY: not on the flood risk listS21 1DA: not on the flood risk listS21 1DB: not on the flood risk listS21 1DD: not on the flood risk listS21 1DE: not on the flood risk listS21 1DF: not on the flood risk listS21 1DG: not on the flood risk listS21 1DH: not on the flood risk listS21 1DJ: not on the flood risk listS21 1DL: not on the flood risk listS21 1DP: not on the flood risk listS21 1DQ: not on the flood risk listS21 1DR: not on the flood risk listS21 1DS: not on the flood risk listS21 1DT: not on the flood risk listS21 1DU: not on the flood risk listS21 1DW: not on the flood risk listS21 1EG: not on the flood risk listS21 1EH: not on the flood risk listS21 1EJ: not on the flood risk listS21 1EL: not on the flood risk listS21 1EP: not on the flood risk listS21 1EQ: not on the flood risk listS21 1ER: not on the flood risk listS21 1ET: not on the flood risk listS21 1EU: not on the flood risk listS21 1EW: not on the flood risk listS21 1EX: not on the flood risk listS21 1EY: not on the flood risk listS21 1EZ: not on the flood risk listS21 1FA: not on the flood risk listS21 1FB: not on the flood risk listS21 1FD: not on the flood risk listS21 1FE: not on the flood risk listS21 1FF: not on the flood risk listS21 1FG: not on the flood risk listS21 1FH: not on the flood risk listS21 1FJ: not on the flood risk listS21 1FL: not on the flood risk listS21 1FN: not on the flood risk listS21 1FP: not on the flood risk listS21 1FQ: not on the flood risk listS21 1FR: not on the flood risk listS21 1FS: not on the flood risk listS21 1FT: not on the flood risk listS21 1FU: not on the flood risk listS21 1FW: not on the flood risk listS21 1FX: not on the flood risk listS21 1FY: not on the flood risk listS21 1FZ: not on the flood risk listS21 1GA: not on the flood risk listS21 1GB: not on the flood risk listS21 1GD: not on the flood risk listS21 1GE: not on the flood risk listS21 1GF: not on the flood risk listS21 1GG: not on the flood risk listS21 1GH: not on the flood risk listS21 1GJ: not on the flood risk listS21 1GL: not on the flood risk listS21 1GN: not on the flood risk listS21 1GP: not on the flood risk listS21 1GQ: not on the flood risk listS21 1GR: not on the flood risk listS21 1GS: not on the flood risk listS21 1GT: not on the flood risk listS21 1GU: not on the flood risk listS21 1GW: not on the flood risk listS21 1GX: not on the flood risk listS21 1GY: not on the flood risk listS21 1HA: not on the flood risk listS21 1HB: not on the flood risk listS21 1HD: not on the flood risk listS21 1HE: not on the flood risk listS21 1HF: not on the flood risk listS21 1HG: not on the flood risk listS21 1HH: not on the flood risk listS21 1HJ: not on the flood risk listS21 1HL: not on the flood risk listS21 1HN: not on the flood risk listS21 1HP: not on the flood risk listS21 1HQ: not on the flood risk listS21 1HR: not on the flood risk listS21 1HS: not on the flood risk listS21 1HT: not on the flood risk listS21 1HU: not on the flood risk listS21 1HW: not on the flood risk listS21 1HY: not on the flood risk listS21 1HZ: not on the flood risk listS21 1JA: not on the flood risk listS21 1JD: not on the flood risk listS21 1JF: not on the flood risk listS21 1JG: not on the flood risk listS21 1JH: not on the flood risk listS21 1JJ: not on the flood risk listS21 1JL: not on the flood risk listS21 1JN: not on the flood risk listS21 1JP: not on the flood risk listS21 1JQ: not on the flood risk listS21 1JR: not on the flood risk listS21 1JS: not on the flood risk listS21 1JT: not on the flood risk listS21 1JU: not on the flood risk listS21 1JW: not on the flood risk listS21 1JX: not on the flood risk listS21 1JZ: not on the flood risk listS21 1LB: not on the flood risk listS21 1LD: not on the flood risk listS21 1LE: not on the flood risk listS21 1LF: not on the flood risk listS21 1LG: not on the flood risk listS21 1LH: not on the flood risk listS21 1LX: not on the flood risk listS21 1NE: not on the flood risk listS21 1NF: not on the flood risk listS21 1NJ: not on the flood risk listS21 1NL: not on the flood risk listS21 1NN: not on the flood risk listS21 1SH: not on the flood risk listS21 1SP: not on the flood risk listS21 1SW: not on the flood risk listS21 1SX: not on the flood risk listS21 1TA: not on the flood risk listS21 1TB: not on the flood risk listS21 1TD: not on the flood risk listS21 1TF: not on the flood risk listS21 1TG: not on the flood risk listS21 1TH: not on the flood risk listS21 1TL: not on the flood risk listS21 1TQ: not on the flood risk listS21 1TW: not on the flood risk listS21 1TZ: not on the flood risk listS21 1DN: very low flood risk onlyS21 1DZ: very low flood risk onlyS21 1EA: very low flood risk onlyS21 1EB: very low flood risk onlyS21 1EE: very low flood risk onlyS21 1EF: very low flood risk onlyS21 1EN: very low flood risk onlyS21 1ES: very low flood risk onlyS21 1HX: very low flood risk onlyS21 1TE: very low flood risk onlyS21 1TN: very low flood risk onlyS21 1DX: low flood risk at worstS21 1DY: low flood risk at worstS21 1ED: low flood risk at worstS21 1AS: medium flood risk at worstS21 1JE: medium flood risk at worstS21 1JY: medium flood risk at worstS21 1AU: high flood riskS21 1BZ: high flood riskS21 1GZ: high flood riskS21 1JB: high flood risk Killamarsh Map of every postcode in the S21 1 sector, by flood risk Of the 187 postcodes in the S21 1 sector that ONS places, 4 have a home or business at high risk, 3 are at medium risk at worst, 3 are at low risk at worst, 11 are at very low risk only and 166 are not on the Environment Agency's at-risk list. One postcode lies beyond the edge and is listed under the map. Places named: Killamarsh. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 500 m. Killamarsh
  • A home or business at high risk: 4
  • At medium risk at worst: 3
  • At low risk at worst: 3
  • At very low risk only: 11
  • Not on the at-risk list: 166

Of the 187 postcodes in the S21 1 sector that ONS places, 4 have a home or business at high risk, 3 are at medium risk at worst, 3 are at low risk at worst, 11 are at very low risk only and 166 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.

S21 1BZ6 at high riskS21 1GZ5 at high riskS21 1JB2 at high riskS21 1AU2 at high risk

Further out, not drawn

This postcode lies well apart from the rest, so the map is drawn without it to show the rest closer; it is in every count.

S21 1BQ

What do homes sell for in S21 1?

Homes in S21 1 sold for a typical £231,500 in the 12 months to August 2026, across 72 sales, up 8.2% on the 12 months before, HM Land Registry's figures show.

£231,500 typical price, the 12 months to August 2026
£214,000 12 months to August 2025
▲ up 8.2% on the 12 months before
  • Detached £288,625 32 sales
  • Semi-detached £198,975 28 sales
  • Terraced £206,550 12 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 S21 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 S21 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.

S21 1AAS21 1ABS21 1ADS21 1AES21 1AFS21 1AGS21 1AHS21 1ALS21 1ANS21 1APS21 1AQS21 1ARS21 1ASS21 1ATS21 1AUS21 1AWS21 1AXS21 1AYS21 1AZS21 1BAS21 1BBS21 1BDS21 1BES21 1BFS21 1BGS21 1BHS21 1BJS21 1BLS21 1BNS21 1BPS21 1BQS21 1BRS21 1BSS21 1BTS21 1BUS21 1BWS21 1BXS21 1BYS21 1BZS21 1DAS21 1DBS21 1DDS21 1DES21 1DFS21 1DGS21 1DHS21 1DJS21 1DLS21 1DNS21 1DPS21 1DQS21 1DRS21 1DSS21 1DTS21 1DUS21 1DWS21 1DXS21 1DYS21 1DZS21 1EAS21 1EBS21 1EDS21 1EES21 1EFS21 1EGS21 1EHS21 1EJS21 1ELS21 1ENS21 1EPS21 1EQS21 1ERS21 1ESS21 1ETS21 1EUS21 1EWS21 1EXS21 1EYS21 1EZS21 1FAS21 1FBS21 1FDS21 1FES21 1FFS21 1FGS21 1FHS21 1FJS21 1FLS21 1FNS21 1FPS21 1FQS21 1FRS21 1FSS21 1FTS21 1FUS21 1FWS21 1FXS21 1FYS21 1FZS21 1GAS21 1GBS21 1GDS21 1GES21 1GFS21 1GGS21 1GHS21 1GJS21 1GLS21 1GNS21 1GPS21 1GQS21 1GRS21 1GSS21 1GTS21 1GUS21 1GWS21 1GXS21 1GYS21 1GZS21 1HAS21 1HBS21 1HDS21 1HES21 1HFS21 1HGS21 1HHS21 1HJS21 1HLS21 1HNS21 1HPS21 1HQS21 1HRS21 1HSS21 1HTS21 1HUS21 1HWS21 1HXS21 1HYS21 1HZS21 1JAS21 1JBS21 1JDS21 1JES21 1JFS21 1JGS21 1JHS21 1JJS21 1JLS21 1JNS21 1JPS21 1JQS21 1JRS21 1JSS21 1JTS21 1JUS21 1JWS21 1JXS21 1JYS21 1JZS21 1LBS21 1LDS21 1LES21 1LFS21 1LGS21 1LHS21 1LXS21 1NES21 1NFS21 1NJS21 1NLS21 1NNS21 1SHS21 1SPS21 1SWS21 1SXS21 1TAS21 1TBS21 1TDS21 1TES21 1TFS21 1TGS21 1THS21 1TLS21 1TNS21 1TQS21 1TWS21 1TZ

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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