What an ITF-14 number contains
ITF-14 barcodes carry a GTIN-14, which identifies a case or carton of products rather than a single item. The 14 digits are:
- Indicator digit (1st): 1–8 distinguish pack configurations of the same product (for example a case of 6 and a case of 24). 9 marks variable-measure items. 0 means the carton uses the item's own GTIN-13 or GTIN-12.
- Company prefix and item reference (next 12): usually the same as the product's EAN-13 without its check digit.
- Check digit (last): calculated again over all 13 preceding digits.
For example, a product with EAN-13 5012345678900 packed in cases could use GTIN-14 15012345678907: indicator 1, the same 12 digits, and a new check digit. The check digit changes because the indicator digit is part of the calculation, so you can't simply put a digit in front of an EAN-13.
Purpose of the check digit
Warehouse scanners and people typing numbers into systems both make mistakes. The last digit is calculated from the other 13 using the GS1 mod 10 method (weights 3 and 1 alternating from the right). If any single digit is misread or mistyped, the calculation no longer matches, and the error is caught before the wrong carton is shipped or received.
Printing ITF-14
ITF-14 is designed for corrugated cardboard, so it's printed large (a narrow bar of about 0.5–1 mm) with a thick bearer bar border that stops scanners reading a partial code. Create one with the ITF-14 generator.