A method of electronically endorsing a check includes obtaining an electronic image of the check and composing an endorsement data element for the check that includes at least first information identifying a party endorsing the check. The method further includes creating a message data file including the electronic image and the endorsement data element, and creating a signed message data file that includes the message data file and a digital signature of the message data file creating using a private key. The private key may be specific to the party endorsing the check or to an electronic device with which the method is implemented. Also, a method of performing an inquiry relating to a check that was endorsed as described above using the endorsement data element.