Wonga chief operating officer Niall Wass has urged the Archbishop of Canterbury, a critic of the firm, to try out the payday lender.
"What I'm asking him and others to do - go use the service. See if you think it's fair and transparent," he told ITV News Business Editor Laura Kuenssberg.
"Take out £10 for 30 days. Pay it back after a week - which you can't do in many other places. Look at the price, tell me if that's fair and transparent.
"And then judge us by our customers. Our customers are regular people."