SO21 3 postcode sector in the SO21 district

SO21 3 is a sector of the SO21 district: every postcode that starts SO21 3. It has 243 postcodes in use, 2 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 SO21 3 sector, by flood risk

Map of every postcode in the SO21 3 sector, by flood risk Of the 243 postcodes in the SO21 3 sector that ONS places, 7 have a home or business at high risk, 7 are at medium risk at worst, 4 are at low risk at worst and 225 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: Kings Worthy. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. A33A30A34A272 SO21 3AA: not on the flood risk listSO21 3AB: not on the flood risk listSO21 3AD: not on the flood risk listSO21 3AE: not on the flood risk listSO21 3AF: not on the flood risk listSO21 3AG: not on the flood risk listSO21 3AH: not on the flood risk listSO21 3AJ: not on the flood risk listSO21 3AL: not on the flood risk listSO21 3AN: not on the flood risk listSO21 3AP: not on the flood risk listSO21 3AQ: not on the flood risk listSO21 3AR: not on the flood risk listSO21 3AS: not on the flood risk listSO21 3AT: not on the flood risk listSO21 3AU: not on the flood risk listSO21 3AW: not on the flood risk listSO21 3AY: not on the flood risk listSO21 3AZ: not on the flood risk listSO21 3BA: not on the flood risk listSO21 3BB: not on the flood risk listSO21 3BD: not on the flood risk listSO21 3BE: not on the flood risk listSO21 3BF: not on the flood risk listSO21 3BG: not on the flood risk listSO21 3BH: not on the flood risk listSO21 3BJ: not on the flood risk listSO21 3BL: not on the flood risk listSO21 3BN: not on the flood risk listSO21 3BP: not on the flood risk listSO21 3BQ: not on the flood risk listSO21 3BS: not on the flood risk listSO21 3BT: not on the flood risk listSO21 3BU: not on the flood risk listSO21 3BX: not on the flood risk listSO21 3BY: not on the flood risk listSO21 3BZ: not on the flood risk listSO21 3DA: not on the flood risk listSO21 3DE: not on the flood risk listSO21 3DG: not on the flood risk listSO21 3DJ: not on the flood risk listSO21 3DL: not on the flood risk listSO21 3DN: not on the flood risk listSO21 3DP: not on the flood risk listSO21 3DQ: not on the flood risk listSO21 3DR: not on the flood risk listSO21 3DS: not on the flood risk listSO21 3DU: not on the flood risk listSO21 3DW: not on the flood risk listSO21 3DX: not on the flood risk listSO21 3DY: not on the flood risk listSO21 3DZ: not on the flood risk listSO21 3EA: not on the flood risk listSO21 3EB: not on the flood risk listSO21 3ED: not on the flood risk listSO21 3EE: not on the flood risk listSO21 3EG: not on the flood risk listSO21 3EH: not on the flood risk listSO21 3EJ: not on the flood risk listSO21 3EL: not on the flood risk listSO21 3EN: not on the flood risk listSO21 3EP: not on the flood risk listSO21 3EQ: not on the flood risk listSO21 3ER: not on the flood risk listSO21 3ES: not on the flood risk listSO21 3ET: not on the flood risk listSO21 3EU: not on the flood risk listSO21 3EW: not on the flood risk listSO21 3EY: not on the flood risk listSO21 3FE: not on the flood risk listSO21 3FF: not on the flood risk listSO21 3FG: not on the flood risk listSO21 3FJ: not on the flood risk listSO21 3FL: not on the flood risk listSO21 3FN: not on the flood risk listSO21 3FP: not on the flood risk listSO21 3FQ: not on the flood risk listSO21 3FS: not on the flood risk listSO21 3FT: not on the flood risk listSO21 3FU: not on the flood risk listSO21 3FW: not on the flood risk listSO21 3FX: not on the flood risk listSO21 3FY: not on the flood risk listSO21 3GA: not on the flood risk listSO21 3GZ: not on the flood risk listSO21 3HA: not on the flood risk listSO21 3HB: not on the flood risk listSO21 3HD: not on the flood risk listSO21 3HE: not on the flood risk listSO21 3HH: not on the flood risk listSO21 3HL: not on the flood risk listSO21 3HN: not on the flood risk listSO21 3HP: not on the flood risk listSO21 3HR: not on the flood risk listSO21 3HS: not on the flood risk listSO21 3HT: not on the flood risk listSO21 3HU: not on the flood risk listSO21 3HW: not on the flood risk listSO21 3JA: not on the flood risk listSO21 3JB: not on the flood risk listSO21 3JD: not on the flood risk listSO21 3JE: not on the flood risk listSO21 3JL: not on the flood risk listSO21 3JN: not on the flood risk listSO21 3JS: not on the flood risk listSO21 3JU: not on the flood risk listSO21 3JX: not on the flood risk listSO21 3JY: not on the flood risk listSO21 3LB: not on the flood risk listSO21 3LE: not on the flood risk listSO21 3LF: not on the flood risk listSO21 3LG: not on the flood risk listSO21 3LH: not on the flood risk listSO21 3LJ: not on the flood risk listSO21 3LL: not on the flood risk listSO21 3LN: not on the flood risk listSO21 3LP: not on the flood risk listSO21 3LQ: not on the flood risk listSO21 3LR: not on the flood risk listSO21 3LS: not on the flood risk listSO21 3LW: not on the flood risk listSO21 3LX: not on the flood risk listSO21 3NA: not on the flood risk listSO21 3NB: not on the flood risk listSO21 3ND: not on the flood risk listSO21 3NE: not on the flood risk listSO21 3NF: not on the flood risk listSO21 3NJ: not on the flood risk listSO21 3NP: not on the flood risk listSO21 3NR: not on the flood risk listSO21 3NS: not on the flood risk listSO21 3NT: not on the flood risk listSO21 3NU: not on the flood risk listSO21 3NX: not on the flood risk listSO21 3NY: not on the flood risk listSO21 3NZ: not on the flood risk listSO21 3PA: not on the flood risk listSO21 3PB: not on the flood risk listSO21 3PD: not on the flood risk listSO21 3PE: not on the flood risk listSO21 3PG: not on the flood risk listSO21 3PH: not on the flood risk listSO21 3PL: not on the flood risk listSO21 3PN: not on the flood risk listSO21 3PR: not on the flood risk listSO21 3PS: not on the flood risk listSO21 3PT: not on the flood risk listSO21 3PW: not on the flood risk listSO21 3PX: not on the flood risk listSO21 3PY: not on the flood risk listSO21 3PZ: not on the flood risk listSO21 3QA: not on the flood risk listSO21 3QB: not on the flood risk listSO21 3QD: not on the flood risk listSO21 3QF: not on the flood risk listSO21 3QG: not on the flood risk listSO21 3QH: not on the flood risk listSO21 3QQ: not on the flood risk listSO21 3QR: not on the flood risk listSO21 3QS: not on the flood risk listSO21 3QX: not on the flood risk listSO21 3RB: not on the flood risk listSO21 3RD: not on the flood risk listSO21 3RE: not on the flood risk listSO21 3RG: not on the flood risk listSO21 3RJ: not on the flood risk listSO21 3RL: not on the flood risk listSO21 3RP: not on the flood risk listSO21 3RQ: not on the flood risk listSO21 3RS: not on the flood risk listSO21 3RT: not on the flood risk listSO21 3RU: not on the flood risk listSO21 3RW: not on the flood risk listSO21 3RX: not on the flood risk listSO21 3RY: not on the flood risk listSO21 3SA: not on the flood risk listSO21 3SB: not on the flood risk listSO21 3SD: not on the flood risk listSO21 3SE: not on the flood risk listSO21 3SG: not on the flood risk listSO21 3SH: not on the flood risk listSO21 3SJ: not on the flood risk listSO21 3ST: not on the flood risk listSO21 3SU: not on the flood risk listSO21 3TA: not on the flood risk listSO21 3XA: not on the flood risk listSO21 3LA: low flood risk at worstSO21 3LD: low flood risk at worstSO21 3PF: low flood risk at worstSO21 3RR: low flood risk at worstSO21 3DB: medium flood risk at worstSO21 3GX: medium flood risk at worstSO21 3JG: medium flood risk at worstSO21 3SF: medium flood risk at worstSO21 3RA: medium flood risk at worstSO21 3BW: high flood riskSO21 3DD: high flood riskSO21 3DF: high flood riskSO21 3DT: high flood riskSO21 3FR: high flood riskSO21 3QJ: high flood riskSO21 3RH: high flood risk Kings Worthy 5 postcodes at high or medium risk, outlined: this goes to SO21 3JH, the one with most homes and businesses at high risk5 postcodes at high or medium risk Map of every postcode in the SO21 3 sector, by flood risk Of the 243 postcodes in the SO21 3 sector that ONS places, 7 have a home or business at high risk, 7 are at medium risk at worst, 4 are at low risk at worst and 225 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: Kings Worthy. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. Kings Worthy
  • A home or business at high risk: 7
  • At medium risk at worst: 7
  • At low risk at worst: 4
  • At very low risk only: 0
  • Not on the at-risk list: 225
  • Outline: where 5 or more postcodes at high or medium risk lie together

Of the 243 postcodes in the SO21 3 sector that ONS places, 7 have a home or business at high risk, 7 are at medium risk at worst, 4 are at low risk at worst and 225 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 250 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.

SO21 3RH5 at high riskSO21 3DF2 at high riskSO21 3BW1 at high riskSO21 3DT1 at high riskSO21 3QJ1 at high riskSO21 3DD1 at high riskSO21 3FR1 at high risk

Where the postcodes at high or medium risk lie together

  • 5 postcodes at high or medium risk, outlined on the map. SO21 3JH, is the one with most homes and businesses at high risk.

What do homes sell for in SO21 3?

Homes in SO21 3 sold for a typical £542,500 in the 12 months to August 2026, across 56 sales, down 7.3% on the 12 months before, HM Land Registry's figures show.

£542,500 typical price, the 12 months to August 2026
£585,000 12 months to August 2025
▼ down 7.3% on the 12 months before
  • Detached £630,000 29 sales
  • Semi-detached £425,000 14 sales
  • Terraced £410,000 10 sales
  • Flat or maisonette 3 sales, too few to price

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 SO21 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 SO21 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.

SO21 3AASO21 3ABSO21 3ADSO21 3AESO21 3AFSO21 3AGSO21 3AHSO21 3AJSO21 3ALSO21 3ANSO21 3APSO21 3AQSO21 3ARSO21 3ASSO21 3ATSO21 3AUSO21 3AWSO21 3AXSO21 3AYSO21 3AZSO21 3BASO21 3BBSO21 3BDSO21 3BESO21 3BFSO21 3BGSO21 3BHSO21 3BJSO21 3BLSO21 3BNSO21 3BPSO21 3BQSO21 3BSSO21 3BTSO21 3BUSO21 3BWSO21 3BXSO21 3BYSO21 3BZSO21 3DASO21 3DBSO21 3DDSO21 3DESO21 3DFSO21 3DGSO21 3DHSO21 3DJSO21 3DLSO21 3DNSO21 3DPSO21 3DQSO21 3DRSO21 3DSSO21 3DTSO21 3DUSO21 3DWSO21 3DXSO21 3DYSO21 3DZSO21 3EASO21 3EBSO21 3EDSO21 3EESO21 3EFSO21 3EGSO21 3EHSO21 3EJSO21 3ELSO21 3ENSO21 3EPSO21 3EQSO21 3ERSO21 3ESSO21 3ETSO21 3EUSO21 3EWSO21 3EXSO21 3EYSO21 3EZSO21 3FASO21 3FBSO21 3FDSO21 3FESO21 3FFSO21 3FGSO21 3FHSO21 3FJSO21 3FLSO21 3FNSO21 3FPSO21 3FQSO21 3FRSO21 3FSSO21 3FTSO21 3FUSO21 3FWSO21 3FXSO21 3FYSO21 3GASO21 3GXSO21 3GYSO21 3GZSO21 3HASO21 3HBSO21 3HDSO21 3HESO21 3HFSO21 3HGSO21 3HHSO21 3HJSO21 3HLSO21 3HNSO21 3HPSO21 3HQSO21 3HRSO21 3HSSO21 3HTSO21 3HUSO21 3HWSO21 3HXSO21 3HYSO21 3HZSO21 3JASO21 3JBSO21 3JDSO21 3JESO21 3JFSO21 3JGSO21 3JHSO21 3JJSO21 3JLSO21 3JNSO21 3JPSO21 3JRSO21 3JSSO21 3JTSO21 3JUSO21 3JWSO21 3JXSO21 3JYSO21 3LASO21 3LBSO21 3LDSO21 3LESO21 3LFSO21 3LGSO21 3LHSO21 3LJSO21 3LLSO21 3LNSO21 3LPSO21 3LQSO21 3LRSO21 3LSSO21 3LTSO21 3LUSO21 3LWSO21 3LXSO21 3NASO21 3NBSO21 3NDSO21 3NESO21 3NFSO21 3NHSO21 3NJSO21 3NLSO21 3NPSO21 3NRSO21 3NSSO21 3NTSO21 3NUSO21 3NXSO21 3NYSO21 3NZSO21 3PASO21 3PBSO21 3PDSO21 3PESO21 3PFSO21 3PGSO21 3PHSO21 3PJSO21 3PLSO21 3PNSO21 3PPSO21 3PQSO21 3PRSO21 3PSSO21 3PTSO21 3PWSO21 3PXSO21 3PYSO21 3PZSO21 3QASO21 3QBSO21 3QDSO21 3QFSO21 3QGSO21 3QHSO21 3QJSO21 3QQSO21 3QRSO21 3QSSO21 3QXSO21 3QYSO21 3QZSO21 3RASO21 3RBSO21 3RDSO21 3RESO21 3RFSO21 3RGSO21 3RHSO21 3RJSO21 3RLSO21 3RNSO21 3RPSO21 3RQSO21 3RRSO21 3RSSO21 3RTSO21 3RUSO21 3RWSO21 3RXSO21 3RYSO21 3RZSO21 3SASO21 3SBSO21 3SDSO21 3SESO21 3SFSO21 3SGSO21 3SHSO21 3SJSO21 3SLSO21 3SNSO21 3SPSO21 3SRSO21 3STSO21 3SUSO21 3TASO21 3XASO21 3XX

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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