US Patent 11893443 Transaction card assembly

A modular transaction card assembly includes a card frame having the traditional dimensions of a credit card, and a transaction card that is smaller than a traditional card and that fits into a receptacle of the card frame. Each of the card frame and the transaction card may be capable of performing contactless data transactions individually. In some instances, the combined assembly of the card frame with the transaction card may detect a proximity of a mobile device to the assembly and generate an authentication credential that is unique to the combination of the card frame, the transaction card, and the mobile device. The authentication credential may be used to authentic the transaction card when conducting a data transaction.