Acceptance supra protest is a special type of acceptance of a bill of exchange made by a third party after the bill has been dishonoured and protested.

It happens when:

The original drawee refuses to accept the bill

The bill is officially protested for non-acceptance

Another person (not originally liable) accepts the bill to protect the honour of one of the parties

This third party agrees to pay the bill on the due date if the original drawee still fails to pay.

In simple terms, acceptance supra protest is when someone else accepts a dishonoured bill to save the credit or reputation of a party involved.