The present disclosure describes a computer-implemented platform for managing electronic endorsable instruments and electronic endorser verification information in order to validate endorser identity. A computer system receives an endorsable electronic instrument and a mobile phone number associated with a targeted potential endorser. The endorsable electronic instrument and a verification information request are sent to the mobile phone number by sending a link to an endorsement application via a message to the mobile phone number. The endorsed electronic instrument and corresponding verification information are received and are associated to validate the endorsed instrument.