The present invention provides a method, printer, system and software for verifying that a document was printed by a printer with a printing subsystem having a printhead cartridge with a unique printhead cartridge identifier and having a printhead electronically coupled to a computer. The method includes generating, by the computer, a unique document identification composite of electronic form characters utilizing the unique printhead cartridge identifier and transmitting the unique document identification composite to the printing subsystem for printing thereof on each print media sheet of the document.