After a week of near-constant outages for prepaid card users, Monzo affirms its third-party marketplace will become fundamental to its business model. To break it down, the cost of the pre-paid card is £50 per customer, per year. On the current account, that decreases to £15 per customer per year. As Monzo’s costs come down, Hewinson sees the marketplace as a way to “plug a relatively small gap from a revenue perspective”.