How does the sampling work?

The Navigo Liberté + contract is subject only to a direct debit.

You will be charged every month for the amount of the journeys made during the previous month (with any deductions, fees and refunds).

The direct debit is made between the 13th and 18th of the month for the invoice relating to the previous month. You will be notified in advance, by e-mail, of the amount debited.
If you haven't travelled, you won't receive a direct debit notification.