The original Post Office Savings Bank was limited to deposits of £30 per year with a maximum balance of £150. Interest was paid at the rate of 2.5 percent per annum on whole pounds in the account. Later, the limits were raised to a maximum of £500 per year in deposits with no limit on the total amount. Within five years of the system's establishment, there were over 600,000 accounts and £8.2 million on deposit. By 1927, there were twelve million accounts—one in four Britons—with £283 million (£ million today) on deposit.