A secure self-mailing financial instrument for payments/fund transfers and methods for processing are disclosed which provide a packaging mailer with a detachable securely printed financial instrument attached for the purpose of facilitating secure and convenient delivery of funds for fund transfers, payments, or purchases, including methods for assembling, opening, and preparing for shipment and for processing locally at one of a point of sale location and a website that provides a service to remotely process preparation, shipment, and delivery of the financial instrument as a mailer, as well as for remote printing, processing, folding and sealing, and tracking.