The OPUS card is a smart card on which you can charge all STM transit fares, with the exception of group fares, which are available only on tickets. The OPUS card is used by transit companies throughout the Greater Montréal area.
Read more about the OPUS card
Tickets are meant to be used just once and are not rechargeable.
Read more about tickets
The occasional card is a non-rechargeable smart card. It can contain regular transit fares and is valid for pre-determined periods.
Read more about occasional cards
To pay reduced fares, you must charge your transit fares on a registered photo ID OPUS card.
Read more about registered photo ID OPUS cards