Nationwide Building Society is the world's largest building society, serving over 16 million members. It operates as a British mutual financial institution, meaning it is owned by and run for the benefit of its members. Nationwide is also the seventh largest cooperative financial institution globally. The society's headquarters are located in Swindon, England. Nationwide Building Society was established through the amalgamation of approximately 250 smaller building societies over its history. Among the most notable mergers were the acquisition of Anglia Building Society in 1987 and the Portman Building Society in 2007. As of 2022, Nationwide ranked as the second largest provider of household savings and mortgages in the UK, holding a 10.3% market share in current accounts. For the financial year 2021/2022, Nationwide had assets of around £272.4 billion compared to £483 billion for the entire building society sector, making it larger than the remaining 42 British building societies combined. As of October 2023, Nationwide had a larger number of branches than all other banking brands in the UK. Wikipedia