LL21 postcode district

Postcodes and sectors

368 of the district's 424 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 52.98995, -3.41099, which locates the district, not a building.

Companies registered in LL21

Companies House lists 283 companies with a registered office in LL21; none of them at an address 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 LL21

• Wales
• Sir Ddinbych
• Denbighshire
• Conwy
• Corwen
• Cynwyd
• Llandrillo
• Cerrigydrudion
• Clawdd Poncen
• Carrog
• Bryneglwys
• Gwyddelwern
• Gwynedd
• Glyndyfrdwy
• Bettws Gwerfil Goch
• Llangwm
• Llidiart-y-Parc
• Maerdy
• Druid
• Derwen
• Cefn-brith
• Glan-yr-afon
• Dinmael
• Ty-nant

Roads filed under LL21

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.

• Berwyn Street
• Bridge Street
• Bro Alwen
• Bro Dinam
• Bro Gwerfyl
• Bro Hafryn
• Bro Helyg
• Bryn Elwern
• Bryn Llywelyn
• Cae Bach
• Cae Coed
• Cae Ffynnon
• Cae Llwyd
• Chapel Street
• Clawdd Poncen
• Cwr y Gaer
• Deunant
• Ffordd-Gam Elin
• Ffordd Tan Lan
• Ffordd Ty Cerrig
• Ffordd yr Alwen
• Ffridd y Gog
• Fron Deg Terrace
• Gaer View
• Garreg Lwyd
• Godre'r Coed
• Godre'r Gaer
• Green Lane
• Gwern Gwalia
• Heol-y-Berwyn
• Heol Llundain
• High Street
• Hill Street
• Holyhead Road
• King Street
• Llandrillo Road
• Llys Ial
• Llys Maesydd
• Llys y Coed
• London Road
• Maes-y-Ffynnon
• Maesafallen
• Maes Aled
• Maes Glyndŵr
• Maes Hir
• Maes y Fedwen
• Maes y Glyn
• Maes y Llan
• Mill Street
• Mount Terrace
• Pen y Bryn
• Rhos Helyg
• Rhos Llan
• Rhos Nant
• Stryd Fawr
• Stryd y Bont
• Stryd y Brennig
• Stryd y Capel
• The Crescent
• The Square

Check an address in LL21

Check an address in LL21

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=LL21" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about LL21

What does an LL21 postcode tell you?

That the address lies in the LL21 district of the LL (Llandudno) postcode area, and the place OS Open Names most often lists first for its postcodes is Sir Ddinbych. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 368 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 LL21

• LL1514.1 km
• LL2315.9 km
• LL2017.1 km
• LL1621.8 km
• LL1424.0 km
• SY1025.6 km
• LL2426.2 km
• LL1126.4 km
• CH727.4 km
• SY1128.8 km
• LL1729.2 km
• SY2230.0 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids