Net interest income: Zempler uses customer deposits as overdrafts and loans for other customers.
Treasury income: The Bank of England holds money that isn't used for loans and overdrafts, where it generates interest.
Interchange income: The small fee Zempler takes from card transactions made on certain accounts.
Fees and commission: Zempler upsells credit cards, loans and overdrafts, which generate income through the interest customers must pay back on top of the borrowed amount.