SY21 postcode district

Postcodes and sectors

872 of the district's 1,048 postcodes are live in the ONS Postcode Directory of August 2026. A postcode directory says whether a code is in use, never who is there. The live postcodes centre on 52.65825, -3.20671, which locates the district, not a building.

Companies registered in SY21

Companies House lists 810 companies with a registered office in SY21; 79 of them at addresses shared by 25 or more companies (1 October 2026 snapshot). 25 is the count at which the address lookup reports a company cluster.

Places OS Open Names lists for SY21

• Powys
• Wales
• Y Trallwng
• Welshpool
• Llanfair Caereinion
• Cegidfa
• Guilsfield
• Forden
• Ffordun
• Shropshire
• West Midlands
• Aberriw
• Berriew
• Middletown
• Castell Caereinion
• Castle Caereinion
• Llanerfyl
• Trewern
• Tre'r llai
• Leighton
• Buttington
• Foel
• Llangadfan
• Garthmyl

Roads filed under SY21

Named roads first, then numbered ones. A road is filed under one district even where it runs through several, so a street missing here may be listed under a neighbouring district — which is why the address lookup never calls a British street absent. Great Britain has no open register of buildings, so a listed road never means a building on it exists.

• Abbey Close
• Abbey Lane
• Acorn Rise
• Acrefield Avenue
• Adelaide Drive
• Agincourt Drive
• Albert Terrace
• Arddleen Road
• Aubet Drive
• Banwy Industrial Estate
• Belan Fields
• Belan School Lane
• Berriew Road
• Berriew Street
• Birds Corner
• Bluebell Close
• Blue Bell Drive
• Boot Street
• Borfa Green
• Bowling Green Lane
• Breidden Meadow
• Breidden Place
• Breidden View
• Breidden Way
• Bridge Street
• Brithdir Lane
• Broad Street
• Broncafnent Lane
• Bron Gungrog
• Bronwylfa Road
• Brookfield Road
• Brook Street
• Bryn-y-Castell
• Bryn-y-Ddol
• Bryneglwys
• Brynfa Avenue
• Bryn Glas
• Bryn Lane
• Bryn Siriol
• Bull Dingle
• Burgess Close
• Burgess Croft
• Burgess Road
• Burnt Lane
• Buttington Cross
• Cae Celyn
• Canal Yard
• Castle Walk
• Cefn-Yspin Lane
• Cefn Hawys
• Celyn Close
• Celyn Lane
• Cemetery Lane
• Chapel Fields
• Chapel Street
• Chelsea Lane
• Chepstow Avenue
• Chesnut View
• Chestnut Drive
• Church Bank

Check an address in SY21

Check an address in SY21

The same road list through the API, from the outward code alone:

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=SY21" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about SY21

What does an SY21 postcode tell you?

That the address lies in the SY21 district of the SY (Shrewsbury) postcode area, and the place OS Open Names most often lists first for its postcodes is Powys. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 872 live postcodes.

Where the counts come from

• ons-postcode-directory · version 2026-08 · Contains ONS, OS and Royal Mail data © Crown copyright and database right 2026, Open Government Licence v3.0. Northern Ireland postcodes are excluded: their reuse needs a Land & Property Services licence.
• os-open-names · version 2026-11-01 · Contains OS data © Crown copyright and database right 2026, Open Government Licence v3.0.
• uk-companies-house · version 2026-10-01 · Companies House free company data product, Open Government Licence v3.0

What each figure means, and what a district page never says, is set out in Reading a British postcode district page; the glossary defines a postcode district, a postcode area, a postcode directory and a street register.

Data synced on 2026-11-01: the newest version among the datasets listed above.

Districts nearest SY21

• SY2211.0 km
• SY1512.7 km
• SY1616.9 km
• SY1021.0 km
• SY922.9 km
• SY1723.7 km
• SY525.2 km
• SY1126.4 km
• SY329.5 km
• SY1930.2 km
• SY631.1 km
• SY132.2 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids