# How to identify the product (GTIN)

## GTIN-13-code

The GTIN is usually 13 characters long. The generation of the code depends on the length of the company prefix issued. It should be noted that the GTIN must be unique.

- The 9-digit company prefix issued by GS1 Finland Oy comes as first
- The next 3 numbers you can decide for yourself
- The last, i.e., 13th digit is a check digit calculated from the first 12 digits by a check digit calculator

Example9-digit company prefix + optional own 3 digits 3 digits + verification number

64YYYYYYY + AAA + T

YYYYYYY = company prefix

AAA = own numbers

T = verification number

- The 7-digit company prefix issued by GS1 Finland Oy comes as first
- The next 5 numbers you can decide for yourself
- The last, i.e., 13th digit is a check digit calculated from the first 12 digits by a check digit calculator

Example7-digit company prefix + optional own 5 digits + verification number

64YYYYY + AAAAA + T

YYYYY = company prefix

AAAAA = own numbers

T = verification number

- The first is a series of numbers corresponding to the weight

23 -> products below 10 kg

24 -> products over 10 kg

25 -> products over 100 kg - After this, the company prefix issued by GS1 Finland Oy becomes the last four digits (640 omitted)
- The next two numbers can be decided by yourself
- Next are four numbers that indicate the weight of the product in kilograms (the symbol 23-25 at the beginning determines the position of the comma in the weight)
- The last, i.e., 13th digit is a check digit calculated from the first 12 digits by a check digit calculator

Example23 YYYY AA PPPP T -> products below 10 kg for example. 1.155 kg

24 YYYY AA PPPP T -> products between 10-100 kg for example 11.55 kg

25 YYYY AA PPPP T -> products over 100 kg for example 115.5 kgYYYY = company prefix

AA = own numbers

PPPP = weight of the product

T = verification number

## Generating GTIN-8, GTIN-12, and GTIN-14

In addition to the GTIN-13 code, there are three other GTIN versions: GTIN-14, GTIN-12, and GTIN-8. If the application requires the GTIN to be displayed as 14 digits, a sufficient number of zeros must be added to the beginning.

*It should also be noted that GTIN-8 or GTIN-12 codes cannot be generated from a 9-, 7-, 10-, or 11-digit GS1 company prefix.*

## Note! GTINs are unique and, for example, reusing the GTIN of a discontinued product as an identifier of another product is prohibited.

Variable-length product codes are an exception to this rule. The GTIN on a fresh product of variable length may not be re-used as an identifier for another product of variable size at the earliest: 24 months after the expiry date of the last batch of the expired product.