SO51 9 postcode sector in the SO51 district

SO51 9 is a sector of the SO51 district: every postcode that starts SO51 9. It has 64 postcodes in use, 4 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 SO51 9 sector, by flood risk

Map of every postcode in the SO51 9 sector, by flood risk Of the 64 postcodes in the SO51 9 sector that ONS places, 6 have a home or business at high risk, 1 are at medium risk at worst, 1 are at low risk at worst and 56 are not on the Environment Agency's at-risk list. Places named: Romsey, North Baddesley. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 1 km. M27A3057 SO51 9AA: not on the flood risk listSO51 9AB: not on the flood risk listSO51 9AE: not on the flood risk listSO51 9AF: not on the flood risk listSO51 9AG: not on the flood risk listSO51 9AL: not on the flood risk listSO51 9AP: not on the flood risk listSO51 9AQ: not on the flood risk listSO51 9AS: not on the flood risk listSO51 9AT: not on the flood risk listSO51 9AU: not on the flood risk listSO51 9AW: not on the flood risk listSO51 9AX: not on the flood risk listSO51 9AY: not on the flood risk listSO51 9BA: not on the flood risk listSO51 9BB: not on the flood risk listSO51 9BE: not on the flood risk listSO51 9BG: not on the flood risk listSO51 9BJ: not on the flood risk listSO51 9BL: not on the flood risk listSO51 9BP: not on the flood risk listSO51 9BQ: not on the flood risk listSO51 9BR: not on the flood risk listSO51 9BT: not on the flood risk listSO51 9BU: not on the flood risk listSO51 9BW: not on the flood risk listSO51 9BX: not on the flood risk listSO51 9BY: not on the flood risk listSO51 9BZ: not on the flood risk listSO51 9DA: not on the flood risk listSO51 9DB: not on the flood risk listSO51 9DD: not on the flood risk listSO51 9DE: not on the flood risk listSO51 9DF: not on the flood risk listSO51 9DG: not on the flood risk listSO51 9DH: not on the flood risk listSO51 9DJ: not on the flood risk listSO51 9DL: not on the flood risk listSO51 9DN: not on the flood risk listSO51 9DQ: not on the flood risk listSO51 9LE: not on the flood risk listSO51 9LF: not on the flood risk listSO51 9LG: not on the flood risk listSO51 9LJ: not on the flood risk listSO51 9LL: not on the flood risk listSO51 9LN: not on the flood risk listSO51 9LP: not on the flood risk listSO51 9LQ: not on the flood risk listSO51 9NJ: not on the flood risk listSO51 9PA: not on the flood risk listSO51 9ZD: not on the flood risk listSO51 9ZE: not on the flood risk listSO51 9ZF: not on the flood risk listSO51 9AJ: low flood risk at worstSO51 9LH: medium flood risk at worstSO51 9AN: high flood riskSO51 9BD: high flood riskSO51 9BN: high flood riskSO51 9LA: high flood riskSO51 9LB: high flood riskSO51 9ZH: high flood risk RomseyNorth Baddesley Map of every postcode in the SO51 9 sector, by flood risk Of the 64 postcodes in the SO51 9 sector that ONS places, 6 have a home or business at high risk, 1 are at medium risk at worst, 1 are at low risk at worst and 56 are not on the Environment Agency's at-risk list. Places named: Romsey, North Baddesley. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2 km. A27 RomseyNorth Baddesley
  • A home or business at high risk: 6
  • At medium risk at worst: 1
  • At low risk at worst: 1
  • At very low risk only: 0
  • Not on the at-risk list: 56

Of the 64 postcodes in the SO51 9 sector that ONS places, 6 have a home or business at high risk, 1 are at medium risk at worst, 1 are at low risk at worst and 56 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.

SO51 9AN4 at high riskSO51 9BD2 at high riskSO51 9LA2 at high riskSO51 9BN1 at high riskSO51 9LB1 at high riskSO51 9ZH1 at high risk

What do homes sell for in SO51 9?

Homes in SO51 9 sold for a typical £956,250 in the 12 months to August 2026, across 6 sales, up 6.3% on the 12 months before, HM Land Registry's figures show.

£956,250 typical price, the 12 months to August 2026
£900,000 12 months to August 2025
▲ up 6.3% on the 12 months before
  • Detached £956,250 6 sales

Standard sales of homes at market value at the postcodes that start SO51 9. 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 SO51 9

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.

SO51 9AASO51 9ABSO51 9ADSO51 9AESO51 9AFSO51 9AGSO51 9AHSO51 9AJSO51 9ALSO51 9ANSO51 9APSO51 9AQSO51 9ASSO51 9ATSO51 9AUSO51 9AWSO51 9AXSO51 9AYSO51 9BASO51 9BBSO51 9BDSO51 9BESO51 9BGSO51 9BJSO51 9BLSO51 9BNSO51 9BPSO51 9BQSO51 9BRSO51 9BSSO51 9BTSO51 9BUSO51 9BWSO51 9BXSO51 9BYSO51 9BZSO51 9DASO51 9DBSO51 9DDSO51 9DESO51 9DFSO51 9DGSO51 9DHSO51 9DJSO51 9DLSO51 9DNSO51 9DQSO51 9LASO51 9LBSO51 9LESO51 9LFSO51 9LGSO51 9LHSO51 9LJSO51 9LLSO51 9LNSO51 9LPSO51 9LQSO51 9NJSO51 9PASO51 9ZDSO51 9ZESO51 9ZFSO51 9ZH

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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