An annuity is a retirement product you can choose to buy with all or part of your pension pot. You might choose a lifetime annuity, which pays you a regular income for the rest of your life, or a short-term annuity which lasts for a fixed number of years. A short-term annuity is also known as a fixed-term annuity. It will provide a regular amount of income for a certain time (usually no more than five years), but with the flexibility to change your mind later.