My customers often save their card details. Will they have to authenticate with 3DSecure payment every time their card is charged?

In most cases, customers who save their card details for regular payments only need to authenticate the very first time their card is charged for the particular merchant. Subsequent card transactions for regular payments are known as card on file transactions. Usually, the merchant does not attempt to re-authenticate such transactions unless it suspects fraud; in which case, the customer will be required to authenticate the transaction in the app once again.