Check the product has been PUBLISHED to that customer.
If you are unsure, refer to the 'How to tell if your item is published' article. For Foodstuffs' suppliers, you may like to check that your Category Manager has "requested" that your data be "enriched" - see this article which covers off that process.
If you believe you have done everything correctly, and your customer cannot 'see' your product information, please contact the GS1 Support Team. We can check your customer's NPC account and then raise the issue with them.
phone: 0800 10 23 56