To facilitate conducting a financial transaction via wireless communication between an electronic device and another electronic device, the electronic device determines a unique transaction identifier for the financial transaction based on financial-account information communicated to the other electronic device. The financial-account information specifies a financial account that is used to pay for the financial transaction. Moreover, the unique transaction identifier may be capable of being independently computed by one or more other entities associated with the financial transaction (such as a counterparty in the financial transaction or a payment network that processes payment for the financial transaction) based on the financial-account information communicated by the portable electronic device. The electronic device may also associate receipt information, which is subsequently received from a third party (such as the payment network), with the financial transaction by comparing the determined unique transaction identifier to the computed unique transaction identifier.