An online verification method comprising the steps of: a) generating, by a module at a server, a random code (S_COD1) associated with a subject to be identified; b) recognizing the operating system of a mobile electronic device of the subject and sending, from said module to a mobile electronic device of the subject to be identified, a text message (S_TXT) including the random code (S_COD1) or a hypertext link for selecting the random code (S_COD1); c) receiving, at the mobile electronic device , said text message (S_TXT) including the random code (S_COD2) or the hypertext link; d) acquiring, by means of the at least one electronic image-taking device of the mobile electronic device , at least one first image representing the subject ; e) detecting, by a second acquisition module of a processing unit of the mobile electronic device , the random code (S_COD2) in the body of the text message (S_TXT) and displaying it in a field of a graphical interface represented on the mobile electronic device of the subject , or selecting the hypertext link contained within the body of the text message and displaying the random code in said field of the graphical interface; f) generating, by the second acquisition module of the processing unit of the mobile electronic device , a second image representing the random code (S_COD2) received at the mobile electronic device within said text message (S_TXT) or selected with the hypertext link of the text message; g) processing in a single composite screen page comprising at least two images, the at least one first image representing the subject and the second image representing the random code (S_COD2); h) performing, at the server , a check between the random code (S_COD2) represented in the second image of the single composite screen page and the random code (S_COD1) generated by the server. a) generating, by a module at a server, a random code (S_COD1) associated with a subject to be identified; b) recognizing the operating system of a mobile electronic device of the subject and sending, from said module to a mobile electronic device of the subject to be identified, a text message (S_TXT) including the random code (S_COD1) or a hypertext link for selecting the random code (S_COD1); c) receiving, at the mobile electronic device , said text message (S_TXT) including the random code (S_COD2) or the hypertext link; d) acquiring, by means of the at least one electronic image-taking device of the mobile electronic device , at least one first image representing the subject ; e) detecting, by a second acquisition module of a processing unit of the mobile electronic device , the random code (S_COD2) in the body of the text message (S_TXT) and displaying it in a field of a graphical interface represented on the mobile electronic device of the subject , or selecting the hypertext link contained within the body of the text message and displaying the random code in said field of the graphical interface; f) generating, by the second acquisition module of the processing unit of the mobile electronic device , a second image representing the random code (S_COD2) received at the mobile electronic device within said text message (S_TXT) or selected with the hypertext link of the text message; g) processing in a single composite screen page comprising at least two images, the at least one first image representing the subject and the second image representing the random code (S_COD2); h) performing, at the server , a check between the random code (S_COD2) represented in the second image of the single composite screen page and the random code (S_COD1) generated by the server. <EOS>