You can register the warranty for your new bike at these links:
Giant
https://www.giant-bicycles.com/it/registration
Scott
https://www.scott-sports.com/it/it/support/registration
Wilier
https://wilier.com/it/garanzia
Specialized
https://www.specialized.com/it/it/account/login
Olympia
http://www.olympiacicli.it/it/conditioni-della-garanzia
Megamo
https://www.megamo.com/it/garanzie
Kelly's
https://www.kellysbike.com/en/warranty-en
Conway
https://conway-bikes.de/en/support/assistance-faq/
Kross
Cadex
https://www.cadex-cycling.com/it/registration
Mavic
