KML is from Wikidata The CH postcode area, also known as the Chester postcode area, is a group of 37 postcode districts in north-west England and north-east Wales, which are subdivisions of thirteen post towns. These districts cover west Cheshire (including Chester, Neston and Ellesmere Port), south-west Merseyside (including Birkenhead, Prenton, Wallasey and Wirral) and east Flintshire (including Deeside, Flint, Buckley, Bagillt, Holywell and Mold).