What does an SS99 postcode tell you?

That the address lies in the SS99 district of the SS (Southend-on-Sea) postcode area, and the place OS Open Names most often lists first for its postcodes is Southend-on-Sea. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 84 live postcodes.

SS99 postcode district

SS99, in the SS (Southend-on-Sea) postcode area, has 84 live and 250 terminated postcodes in the ONS Postcode Directory of August 2026, and OS Open Names files 1 road under it.

postcode area	SS (Southend-on-Sea)
live postcodes	84
terminated postcodes	250
sectors	10
roads listed	1
companies registered	5
centroid	51.54825, 0.71358
directory release	2026-08

Postcodes and sectors

84 of the district's 334 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 51.54825, 0.71358, which locates the district, not a building.

sector	live	terminated
SS99 0	0	15
SS99 1	8	44
SS99 2	0	13
SS99 3	1	8
SS99 4	0	7
SS99 5	1	14
SS99 6	35	102
SS99 7	0	4
SS99 8	0	5
SS99 9	39	38

Companies registered in SS99

Companies House lists 5 companies with a registered office in SS99 (1 October 2026 snapshot).

Places OS Open Names lists for SS99

Southend-on-Sea
Eastern

Roads filed under SS99

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.

Forge Way

Check an address in SS99

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

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=SS99" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about SS99

What does an SS99 postcode tell you?: That the address lies in the SS99 district of the SS (Southend-on-Sea) postcode area, and the place OS Open Names most often lists first for its postcodes is Southend-on-Sea. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 84 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 SS99

SS20.4 km
SS11.7 km
SS01.8 km
SS94.4 km
SS45.0 km
SS35.3 km
SS58.1 km
SS68.7 km
SS89.1 km
SS79.5 km
SS1314.3 km
SS1114.4 km
Every district
How a British address is written
Check any address

distance between the districts' centroids

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