A self-custody wallet combination payment card includes an electronic component with storage, a processor, and a near field communications interface. Two programs are stored at the electronic component and, once provisioned, the electronic component stores one or more blockchain addresses and security keys. The two programs can include a payment application which can interface with point of sale terminals (e.g., following EMV specifications) and a crypto application which has the capability to securely store keys and return a signature for blockchain transaction.