Public transport regulations for the Ile-de-France region do not provide for the reimbursement of unused or partially used transportation tickets (purchased individually or in packages of 10).
Tickets purchased individually or in packages of 10 are permanently valid for single use and are issued without an expiration date. Consequently, they can always be used at a later date.
Navigo travel passes (monthly and weekly) and Solidarity transport passes are the only ones that can be refunded, under certain conditions. Travel passes can be fully refunded (100%) if they are cancelled before the period of validity begins. Travel passes can be partially refunded (50%) if they are cancelled within the first 2 days for weekly travel passes, and within the first 10 days for monthly travel passes, due to illness, job loss, or a change of work place. In this case, a medical certificate or letter from the employer must be included with the request for reimbursement.
This information is indicated in the Passenger User Guide displayed in all RATP stations.