The spot price level above which a coupon (for a structured product such as an autocall) will be paid. It is set as a percentage of the underlying’s initial spot price at the time of inception). For example, if the coupon barrier is set to 130% and the initial spot price of the underlying was 1000, the coupon barrier will be set as 1300.

The actual payment of a coupon depends on the coupon style (binary coupon, memory coupon, etc.) and on whether the autocall barrier is monitored on a continuous basis, or not, and on whether it is breached or not.