The Search API from Open Addresses UK searches for UK addresses in an open data set. The API uses JSON over HTTP and supports partial searches as well as multiple query strings (e.g. by postcode, by town). Responses return all data matching the search terms and include a persistent URL for each address. In addition, the addresses use a format similar to the BS7666 standard and include latitude and longitude coordinates for the geographic center of each address's postcode. See the project page for more information or to demo the Search API.