Dating back to 1846, Nationwide is now the largest building society in the world.
One of Nationwide's strengths is its mutual ownership structure, which means it's owned by its customers, rather than private shareholders.
It's the second largest provider of mortgages and savings accounts in the UK.
Its home insurance is underwritten by RSA, which owns brands such as More Than.
Life insurance and other protection products for Nationwide is provided by Legal & General.