GTIN identifies trade items, GLN identifies locations or parties in GS1 use, and SSCC identifies logistic units. Their names and complete lengths are part of the contract; the shared Mod-10 arithmetic does not make the formats interchangeable.
GTIN has four supported lengths
GTIN-8, GTIN-12, GTIN-13, and GTIN-14 contain 8, 12, 13, and 14 digits respectively, including the final check digit. GTIN-12 is commonly carried in a UPC-A symbol, while GTIN-13 is commonly carried in EAN-13. A valid final digit does not determine which carrier is printed or whether the GTIN was assigned correctly.
GLN-13 uses 13 complete digits
A GLN supported here is 13 digits including its check digit. The arithmetic can confirm that the final digit matches the preceding twelve, but it cannot tell whether the number represents a physical location, legal entity, function, or digital location, nor retrieve the associated record.
SSCC-18 identifies a logistic unit
SSCC has 18 complete digits including the check digit. Its 17-digit body receives the same alternating right-anchored weights. CheckDigit validates that numeric structure only; it does not track a pallet, shipment, label, carrier event, or supply-chain status.