This is a harder question to answer than you might imagine. You can't just walk up to your local NatWest with £1bn in used notes. read more
It depends upon the interest rate of the country where you are living. A highly credible investment company pays you up to 10% interest rate if you deposit your one billion pounds for five years. Higher the deposit period like 5 years, 7 years etc higher the interest rate and lower the period means lower the rate. read more