Well, is it a

Voucher

or

Coupon

Most often, somewhere in the presentment, it is referred to as a 'coupon'.

That means it is a "certificate of interest due on a bond"; and, a "piece cut off" to present for payment.

A 'thing certified' (paper memorial of a claim requiring verification) of a 'legal claim or right' due on a "something that binds" (debt).

So, "cut it off" and present it for payment.