The BT Archives house the records of British Telecom, the world's oldest telecommunications company, which traces its history back to the formation of the Electric Telegraphy Company in 1846. Prior to its privatisation in 1984, BT was a public corporation (and before that a government department) and as a result all of the pre-privatisation material in the archives is in the public domain, making it ideal for academic research. Despite this legal availability, however, the physical availability of material in the archive was limited to two days a week in an archive space in Holborn, London. In 2011 the ‘New Connections' project was set up with the aim of making around half a million items from the public archives of British Telecom available in a new digital archive. As part of ‘New Connections', three academic research projects were funded, one of which was the creation and analysis of the British Telecom Correspondence Corpus (BTCC). The era that the archive covers makes it a potentially fascinating source of data for the linguistic study of business correspondence. The mid-nineteenth to latetwentieth century is a crucial period in the development of English business correspondence as the amount of business being conducted by letter increased massively during this period as a result of the Industrial Revolution, the introduction of the Penny Post, and increased access to education both in schools and through composition grammar guides. Despite its importance in the development of business correspondence, this period has received relatively little attention. The aim of constructing the British Telecom Correspondence Corpus was to start addressing this gap in available linguistic data and enable studies into the development of business correspondence from the mid-nineteenth to late-twentieth century.