SA31 postcode district

Postcodes and sectors

580 of the district's 851 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 51.85688, -4.30841, which locates the district, not a building.

Companies registered in SA31

Companies House lists 1,269 companies with a registered office in SA31; 171 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 SA31

• Sir Gaerfyrddin
• Carmarthenshire
• Wales
• Caerfyrddin
• Carmarthen
• Abergwili
• Cwmffrwd
• Trevaughan
• Llanllwch
• Pibwrlwyd
• Ffynnon-ddrain
• Llangunnor

Roads filed under SA31

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 Mead
• Abergwili Road
• Ael y Bryn
• Allt Ioan
• Alltycnap Road
• Allt y Gog
• Anthony Close
• Anthony Way
• Ash Grove
• Awel Tywi
• Bank Lane
• Barnsfield Terrace
• Beech Road
• Belvedere Avenue
• Blue Street
• Brewery Road
• Brickyard Lane
• Bridge Street
• Brithdir
• Bro'r Holl Saint
• Bro Hedydd
• Bro Myrddin
• Bron-y-Dre
• Bronwydd Road
• Bron yr Aur
• Bryn Bugail
• Brynderwen
• Brynglas Crescent
• Bryn Gorwel
• Brynhaul Street
• Brynhyfryd
• Brynmeurig
• Bryn Myrddln
• Brynteg
• Bryntywi
• Bull Lane
• Bwlch Lane
• Cae Bryn Drain
• Cae Celyn
• Cae Crug
• Cae Eithin
• Cae Seiri
• Cambrian Place
• Cambrian Way
• Capel Dewi Road
• Capel Evan Road
• Cardifor Street
• Castell Hywel
• Castell Pigyn Road
• Castle Hill
• Chapel Street
• Church Lane
• Church Street
• Cillefwr Road East
• Cillefwr Road West
• Clos Anthony
• Clos Bolahaul
• Clos Catrin
• Clos Cwnin
• Clos Dyfed

Check an address in SA31

Check an address in SA31

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=SA31" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about SA31

What does an SA31 postcode tell you?

That the address lies in the SA31 district of the SA (Swansea) postcode area, and the place OS Open Names most often lists first for its postcodes is Caerfyrddin. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 580 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 SA31

• SA339.1 km
• SA3210.1 km
• SA1711.3 km
• SA3918.6 km
• SA1619.0 km
• SA1419.4 km
• SA1520.0 km
• SA3421.3 km
• SA3623.4 km
• SA3823.4 km
• SA1824.8 km
• SA4426.0 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids