Communication between retailer and customer

A computing resource comprising

• a communication interface,
• a memory interface,
• one or more processors, and
• one or more memories including computer program code,
• the one or more memories and the computer program code configured to, with the one or more processors, cause the computing resource at least to perform:
• receive, with the communication interface, a registration of a payment card of a user of a mobile apparatus, and a registration of a communication identifier addressing a wireless transceiver of the mobile apparatus and associated with the registration of the payment card, from the mobile apparatus;
• store, with the memory interface, the registration of the payment card, and the registration of the communication identifier;
• receive, with the communication interface, a plurality of transactions of the user, relating to payments with the payment card of a plurality of trades of commodities between the user and a plurality of various retailers;
• generate a plurality of packets, relating to the payments with the payment card, formed on the basis of the received plurality of the transactions;
• insert transaction information relating to the payments and supplementary information into the plurality of the packets;
• and
• transmit, with the communication interface, the plurality of the packets to the mobile apparatus addressed with the communication identifier.