Your Style Number is located on the back of the hangtag that came attached to your luggage as well as on a label sewn into the interior lining of your luggage. It will look something like 105-21-001-4WB. For Costco customers, you can also use the ITM/ART number located on the packaging and/or hangtag that came with your purchase.
You can also enter the collection name of your item(s) in the Style Number field when registering. Just be sure to select the correct size and color of your purchase in the dropdown list.