Building societies are mutual organisations in the UK, which are owned by their members. The building society sector has changed considerably since the first building societies were founded in the 18th century as ‘terminating’ societies – organisations designed to be wound up once all their members had been housed. In the 19th century, permanent building societies began to spring up and by 1910 over 1,700 societies existed with more than 600,000 members and assets in excess of €89 million. The number of building societies has in recent years decreased significantly due to demutualisation and mergers. There are 51 building societies in the UK.