To prevent a misposting by accurately transmitting information, obtained by specially processing an information having the same contents with a document of a conventional system printed on paper, in the form of a two-dimensional bar code in operation wherein even one character should not be misposted to a ledger, not to mention the examination of important operation.

For data posting between input/output devices having a computer, a word processor, a microcomputer, etc., (computer) inside, this misposting prevention system converts the information, generated by processing the whole or a part of information printed on a recording medium such as a paper by using an output device such as a printer or other necessary information, into a two-dimensional bar code without exchanging data directly with electronic communication equipment and prints the two-dimensional bar code on the recording medium such as paper and a computer, etc., reads the printed two-dimensional bar code by a two-dimensional bar code reader when inputting data which should be pasted, so that important information can be transmitted by one operation not through the posting of information from the recording medium such as paper.