What does a DL12 postcode tell you?

That the address lies in the DL12 district of the DL (Darlington) postcode area, which the directory places around County Durham. The inward half of the full postcode narrows it to a street or a building; the district alone does not, and an address written with a district and no inward half cannot be checked against the register.

Does a street listed here mean an address on it exists?

It means OS Open Names lists a road of that name under the district, which is what the address lookup answers as a street-level match. It says nothing about any building on it: Great Britain publishes no open register of buildings, so the lookup answers exists: null there and confirms the street alone.

Who lives at these postcodes?

Nobody on this page. A postcode directory says whether a code is in use, never who is there, and a streets register lists roads, not occupants. The address lookup carries no field about a person and never will.

DL12 postcode district

What the public directories installed here say about the DL12 postcode district: how many of its postcodes are in use, the places OS Open Names lists for them, the streets it files under the district and the district's centroid. Counted from the national postcode directory and OS Open Names on 2026-09-18, and never about who is at an address.

postcode area	DL (Darlington)
live postcodes	726
terminated postcodes	145
streets listed	234
centroid	54.57198, -1.98488
counted on	2026-09-18

Places the directory lists for DL12

OS Open Names places the district's postcodes in these settlements, boroughs, counties and regions, most often first. A town written as any of them matches the directory in an address lookup, and one written as another place in the DL area is reported but not scored.

County Durham
North East
Barnard Castle
Middleton-in-Teesdale
Cotherstone
Startforth
Mickleton
Bowes
Eggleston
Romaldkirk
Whorlton
Stainton Grove
Holwick
Lendings
Newbiggin
Stainton
Lartington
Boldron
Forest-in-Teesdale
Langdon Beck
High Dyke
Dent Bank
Gilmonby
Greta Bridge

Postcodes in use

726 postcodes in DL12 were in use on the day of the count. A postcode directory says whether a code is in use, never who is there. 145 of its 871 postcodes have been terminated: a real address written with one has moved on, which is not the same thing as a typo, and the address lookup scores it rather than refusing it.

Centroid: 54.57198, -1.98488 — the mean of the live postcodes' centroids, which locates the district, not any building in it.

Streets filed under DL12

OS Open Names files 234 roads under DL12. 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.

A67
A688
Abbey Lane
Albert Close
Alston Road
Ashtree Drive
B6276
B6277
B6278
B6281
Back Lane
Bail Hill Road
Baliol Street
Bartlemere
Beaconsfield Court
Bede Kirk
Bede Road
Beech Walk
Billy Lane
Birch Road

the first 20 of 234, alphabetically

Check an address in DL12

The address checker opens on Great Britain with the district in the field: add the street, the number and the full postcode, and it answers the postcode's status, whether the street is filed under the district, and what kind of delivery point the address names.

Check an address in DL12

curl https://spaw.co/api/v1/address \
  -H "Authorization: Bearer sk_live_…" \
  -H "Content-Type: application/json" \
  -d '{"address": "10 Downing Street, London DL12 …", "country": "GB"}'

Common questions about DL12

What does a DL12 postcode tell you?: That the address lies in the DL12 district of the DL (Darlington) postcode area, which the directory places around County Durham. The inward half of the full postcode narrows it to a street or a building; the district alone does not, and an address written with a district and no inward half cannot be checked against the register.
Does a street listed here mean an address on it exists?: It means OS Open Names lists a road of that name under the district, which is what the address lookup answers as a street-level match. It says nothing about any building on it: Great Britain publishes no open register of buildings, so the lookup answers exists: null there and confirms the street alone.
Who lives at these postcodes?: Nobody on this page. A postcode directory says whether a code is in use, never who is there, and a streets register lists roads, not occupants. The address lookup carries no field about a person and never will.

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.

Data synced on 2026-09-18: the newest register or postcode directory copy installed here.

Other districts in DL

Wrong result, or is it about you? If this tool said something you think is wrong, tell us and a person reads it. If Spaw is holding data about you and you never signed up here — a customer may have had your address verified, or reported that a message to it bounced — erase it yourself, confirmed by mail to that address and with no account needed.

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