A system and method for consumer control over card-based transactions and associated accounts. An interface is provided between a merchant or the merchant's bank and the bank or banks at which the consumer has accounts for card-based transactions. The interface acts as an intermediary which is accessible to the consumer so that the consumer may place a variety of controls on card-based transactions. For example, multiple transaction cards may be linked to a single credit account with each card having a different credit limit. As another example, each transaction card may be restricted to a particular merchant. As yet another example, a consumer may link several credit and/or debit accounts to a single transaction card; the consumer may pre-select criteria to be utilized for directing charges for a particular transaction to be applied the different accounts. The consumer may access the interface via a web site or a telephone for making changes and receiving account information. Flexibility and control over the use of transaction cards is, therefore, provided for card-based transactions and for debit and credit accounts used in connection with such card-based transactions.