GY postcode area
postcode area within the United Kingdom
The GY postcode area, also known as Guernsey postcode area, its post town, is a group of 10 consecutive postal districts covering Guernsey, Alderney, Sark, Herm and the two inhabited lesser islets in that region of the Channel Islands. It was established in 1993 as an extension of the United Kingdom postcode system.
Coverage
The approximate coverage of the postal districts. The post town is GUERNSEY for all postcode districts
Previously, both Alderney and Sark were covered by the GY9 district. In March 2009, Royal Mail had "agreed in principle" for the creation of the GY10 district which would cover all addresses on the island of Alderney, leaving just those of smaller Sark in GY9. This was intended to reduce the amount of mail being sent to the wrong island. The States of Alderney opposed doing it that way round, and instead Sark changed from sector GY9 0 to GY10 1 on 5 January 2011.
“GY postcode area” enters the record as postcode area within the United Kingdom. Crown Archives preserves that source wording while asking what postcode, area and within can confirm, complicate or overturn.
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“GY postcode area” is worth following because a concise public description often conceals a longer documentary argument. Here, postcode, area and within provides the most credible route into that argument.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Jul 5, 2026. The linked authority identifier is Q5515093. Authority coordinates are 49.466, -2.546. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1993, 2009 and 2011.
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This entry incorporates text from “GY postcode area” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.