Interleaved 2 of 5 (ITF25)

Interleaved 2 of 5 is a high-density numeric symbology widely used in warehousing, encoding pairs of digits into both bars and spaces for a much more compact code than Standard 2 of 5.

Interleaved 2 of 5 is based on the Standard 2 of 5 symbology, but uses both bar and space width to encode information, so the density of Interleaved 2 of 5 is much higher.

It is primarily used in the warehouse industry.

Interleaved 2 of 5 encodes any even number of numeric characters in the width of both bars and spaces.

It is called "Interleaved" because 2 characters are encoded in a unit of 5 bars and spaces. The even-position character is encoded into bars, while the odd-position character is encoded into spaces. Thus, Interleaved 2 of 5 symbology can only encode data elements with an even number length.

Interleaved 2 of 5 is a numeric symbology. Its character set includes only 10 digital characters (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). Similar to Standard 2 of 5, Interleaved 2 of 5 can include an optional modulo 10 check digit. Interleaved 2 of 5 is a continuous symbology.

• Interleaved 2 of 5 Mod 10
• USS ITF 2/5, I-2/5 or ITF 2of5

A typical Interleaved 2 of 5 barcode has the following structure:

1. A start character 1010
2. The encoded message
3. A stop character 1101

1. Start with the right-most digit in the message; mark the characters as even and odd position. The right-most digit has the even position.
2. Sum all digits in the odd position.
3. Sum all digits in the even position, and then multiply by 3.
4. Add the results of steps 2 and 3.
5. Divide the result of step 4 by 10; the check digit is the value equal to 10 minus the remainder.

Another variant of Interleaved 2 of 5 is ITF-14, which encodes EAN/UCC-14 (also called SCC-14).

Sometimes ITF-14 also includes an add-on symbol with a five-digit input followed by a checksum digit.

The add-on symbol is separated from the primary symbol by white space.