In 1861, the government set up the Post Office Savings Bank a simple savings scheme aiming to encourage ordinary wage earners to provide for themselves against adversity and ill health. They separated from the Post Office in 1969, becoming National Savings. In 1996, they became an Executive Agency of the Chancellor of the Exchequer. NS&I (National Savings and Investments) is now one of the largest savings organizations in the UK, with over 26 million customers and more than £100 billion invested.
These savings are backed by the UK government so your money is very secure.