Following an update to the HSL app (version 5.3.0), you need to strongly authenticate when transferring a season ticket or multi-journey ticket from one phone to another. In practice, this happens, for example, when you buy a new phone and want to use your season or multi-journey ticket on the new phone.
If you have a multi-journey ticket, please note that if you activate a single ticket and then log out of the app or delete the app, you will lose the activated single ticket. Multi-journey tickets are linked to your personal identity code so you will not lose the ticket or the remaining single tickets.
Authentication is easy and fast: you can authenticate on the HSL app, for example, with your online banking credentials.
The update was made because of a need to ensure that a season or multi-journey ticket is on the right person and thus to prevent potential abuse.