Abstract: An exemplary system includes at least one physical computing device that is communicatively coupled, by way of a network, to a retail point of sale (POS) machine, and that receives a transaction identifier from the POS machine, uses the transaction identifier to query an electronic payment system, receives, from the electronic payment system in response to the query, data representative of a pending electronic payment that is associated with the transaction identifier and is awaiting funding, sends data representative of information about the pending electronic payment to the POS machine, the information indicating an amount to fund the pending electronic payment, receives, from the POS machine, a confirmation that the POS machine has received the amount to fund the pending electronic payment, and notifies the electronic payment system that the pending electronic payment has been funded.