Why do I have to provide my phone number when registering? We will only use your phone number to contact you for the preliminary meeting and to send you the password for the app login as an SMS.(wurde automatisch übersetzt) Related articles What is the indexation/price increase? Does the iChange app work on my phone? If I only want to swim, are there extra membership options for that? Do I have a right of withdrawal with my online membership? Pool - How big is the pool?