A GTIN (Global Trade Item Number) consists of a GS1 Company Prefix, a serial number and a check digit. You can find your company prefix in the email you received when you placed your order or by logging in to MyGS1.
The structure of a GTIN looks like this:
730001000 AAA K
730001000 – is the company prefix. It consists of 6 to 9 digits, depending on the size of the number series you ordered.
AAA – is the serial number of each GTIN, for example 000, 001, 002 etc.
K – is the check digit. You can calculate it in the check digit calculator. You can not decide the check digit yourself. Each new number needs a new check digit.