The paper ticket, whether “single” owhetheret,” must be validated in the machine when you get on the bus.
Keep the ticket in good condition so it remains readable throughout the journey, and show it if requested. It does not expire and cannot be transferred to others.
Note: If the validator doesn’t work due to lack of ink (it happens sometimes!), you must write the date and time of the start of your journey on the ticket with a pen.
TIPS: you can find more information about this in the links below.