A multitrack bar code and associated decoding method. Data are encoded into a multitrack bar code according to numerical values which correspond to the characters composing the data. The numerical values are combined into words and corresponding binary strings are chosen, the parity of each binary string being chosen according to the order of the row being encoded. Each row also includes a row check character, and the first row contains a character which checks the number of rows encoded and a data check sum on the data character values. If desired, column check sums can also be computed on each of the data-bearing rows in the multitrack bar code. The multitrack bar code can be encoded according to a numeric shift code when strings of numeric data of at least eight decimal digits are encountered. An alphanumeric shift character causes the multitrack bar code to return to the alphanumeric mode.