Once you’ve used up all the GTINs in your range, it’s impossible to add more using the same prefix. A new prefix will need to be issued.
The illustration below provides details of the different numbering capacities of different length GCPs:
Key:
P = GS1 Company Prefix
I = Item Reference
C = Check Digit
The first 7 to 11 digits are your GS1 Company Prefix (GCP) which you license from GS1 UK. The length of the prefix determines how many numbers you receive – the shorter the GCP, the more numbers you get.
After the GCP, in the middle of the GTIN, we have the item reference digits which are used to uniquely identify your products
The last digit of the GTIN is always a check digit, calculated automatically to ensure integrity.