These are payments that a life assurance company adds to a 'with-profits' policy. Bonuses are usually added at the end of each year, and there may be a final (terminal) bonus when the policy comes to the end of its term. This normally coincides with when you have to repay the mortgage. Bonuses aren't guaranteed and the amount awarded can change each year. However, once a bonus is made by the life company, they can't take it away.