The Midcounties Co-operative is the fourth-largest co-operative in the United Kingdom. It was formed on 24 September 2005 by the merger of the Oxford, Swindon & Gloucester Co-operative Society (OSG) and the West Midlands Co-operative Society (WMCS). The co-operative's geographical trading area spans seven counties, including most of Oxfordshire and Gloucestershire, the area around Swindon in Wiltshire, Worcestershire, Buckinghamshire and additionally the West Midlands county.