The Principality Building Society (Welsh: Cymdeithas Adeiladu'r Principality) is a building society based in Cardiff, Wales. With assets of £10bn it is the largest building society in Wales and the sixth largest in the United Kingdom. Principality Building Society is mutual, which means it is owned by its members rather than shareholders. It serves clients through the internet and telephone as well as at high street branches. It is a member of the Building Societies Association.