An annuity is a contract with an insurance company, purchased with your pension account, which will provide you with an income for the rest of your life. Once you have bought your annuity (and the cancellation period has expired), you cannot (as the law currently stands) normally change it. Therefore, it is important that you consider all your options carefully and select an annuity that suits the financial needs of you and your dependants; both when you retire and in the future.