When registering a brand on Amazon, you need to provide two different numbers: the Brand Registry number and the Product serial number.

The Brand Registry number is a unique digital identifier issued by Amazon to distinguish your brand from other products on the Amazon platform. When submitting a brand registration application, you need to provide a trademark registration certificate or trademark application document to prove that you are the legal owner of the brand.

The product serial number is a unique identifier for your product. When registering a brand, you need to provide at least one product serial number to ensure that the brand's products are correctly classified and identified. The product serial number can be EAN, UPC, ISBN or ASIN, depending on the type of product you sell.

It is worth noting that Amazon requires you to register your brand and pass the brand registration.