What are you trying to do with the UK postal codes? Address lookup or just validation? For validation, there's an official regex (archived, but still useful)

What are you trying to do with the UK postal codes? Address lookup or just validation? For validation, there's an official regex (archived, but still useful) http://www.cabinetoffice.gov.uk/govtalk/schemasstandards/e-gif/datastandards/address/postcode.aspx http://www.cabinetoffice.gov.uk/govtalk/schemasstandards/e-g.... For address lookup there are a couple of ways to go about it. 1. You can buy the rights to the Royal Mail's database. You get to parse the sucker yourself. http://www.poweredbypaf.com/end-user/products/paf-raw-data/ http://www.poweredbypaf.com/end-user/products/paf-raw-data/ 2. You can use a third party system, either over the web, or choose a solution you can host internally. Depending on the type of system you buy you pay by the lookup or by the user (mostly internally hosted systems).