Spotlight On: NS&I's Investment Account The Government-backed savings institution, National Savings & Investment (NS&I), has relaunched its Investment Account as a postal-only account. The interest rate has been increased to 0.75 per cent. Customers will no longer be able to deposit or withdraw cash from their NS&I account at a local post office. Accounts offered by NS&I have looked very attractive in recent years because they are backed by the Treasury. Unlike banks and building societies which have an £85,000 limit on the amount of savings protected in case of an institution going bust, all money in NS&I is safe (unless the Government goes bust). But the accounts offer paltry interest compared to market leaders.