Here are three of MoneySupermarket's best rates for 1 2,3,4 and 5 year bonds. One year fixed rate bonds Ford Money : 1.65% interest, min £500, max £2million, one year, available online only. Savings bonds are a good way to make your money work harder, if you can afford to tie up your cash into a bond. They work differently to easy-access savings accounts, as they come with a fixed rate of interest over the set term, or time period. Series I Savings Bonds Rates & Terms: Calculating Interest Rates. What interest will I get if I buy an I bond now? The composite rate for I bonds issued from November 1, 2019 through April 30, 2020, is 2.22 percent. This rate applies for the first six months you own the bond.