I’m selling a product made by another company. Do I need to get it a GS1 GTIN?

No, the brand owner of a product assigns the GTIN.

To sell a product created or owned by another company, you must use the existing GTIN that has been assigned to that product.

If you don’t know a product’s GTIN, you should contact the product’s supplier or manufacturer to find the GTIN for that product.

If the product doesn't have a GTIN, you may assign a GS1 GTIN to it.