Check if the online shop is authorized by Tissot SA:
TISSOT disclaims any relationship to, or responsibility for, any timepiece or other item bearing the TISSOT name, brand, logo or symbol offered for sale by anyone not being an official TISSOT retailer. Purchasing such an item from an unauthorized party is therefore at the buyer's sole risk, particularly in the case of counterfeit and in case of products purchased on the Internet. No explicit or implicit warranty or servicing or any other obligation shall ensue for TISSOT or for any of its authorized representatives for products sold by unauthorized parties and not accompanied by a duly stamped TISSOT international warranty certificate. For the above reasons and in your own interest, you are invited to acquire only genuine TISSOT watches available exclusively from a legitimate TISSOT official retailer.