What does an SN99 postcode tell you?

That the address lies in the SN99 district of the SN (Swindon) postcode area, and the place OS Open Names most often lists first for its postcodes is Swindon. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 18 live postcodes.

SN99 postcode district

SN99, in the SN (Swindon) postcode area, has 18 live and 11 terminated postcodes in the ONS Postcode Directory of August 2026, and OS Open Names files no road under it.

postcode area	SN (Swindon)
live postcodes	18
terminated postcodes	11
sectors	2
roads listed	0
centroid	51.55200, -1.72254
directory release	2026-08

Postcodes and sectors

18 of the district's 29 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 51.55200, -1.72254, which locates the district, not a building.

sector	live	terminated
SN99 8	18	0
SN99 9	0	11

Places OS Open Names lists for SN99

Swindon
South West

Roads filed under SN99

OS Open Names files no road under SN99, so a street here cannot be confirmed from the register and the lookup answers about the postcode alone.

Check an address in SN99

Common questions about SN99

What does an SN99 postcode tell you?: That the address lies in the SN99 district of the SN (Swindon) postcode area, and the place OS Open Names most often lists first for its postcodes is Swindon. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 18 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 SN99

SN31.9 km
SN14.4 km
SN25.1 km
SN386.2 km
SN67.8 km
SN257.9 km
SN48.1 km
SN268.2 km
SN58.3 km
SN715.2 km
SN816.4 km
RG1719.4 km
Every district
How a British address is written
Check any address

distance between the districts' centroids

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