The Britannia Building Society began life in 1856 as the Leek and Moorland Permanent Benefit Building Society and spent the next century gradually expanding its network in the Midlands. After World War II it pursued "an active merger policy", and swallowed up over forty other building societies. In particular, in 1975 it combined with the Oldbury Britannia Building Society and the merged society decided to adopt the Britannia name.

It is currently committed to retaining its mutual status but like many other building societies has sought to diversify its business away from the traditional deposit taking and mortgage lending; it has an offshore banking subsidiary Britannia International as well as specialist intermediary lending subsidiary trading as Verso. In the financial year 2001 it made operating profits of just under £140 million from an asset base of some £17 billion.