NAB CEO, Ross McEwan, says the proposed acquisition brings scale and deep expertise in unsecured lending, with senior Citi management and 800 staff transferring to the Australian bank post-acqusition.

“The cards and payments sector is rapidly evolving and access to a greater share of payments and transaction data will help drive product and service innovation across our Personal Banking business and deliver market leading customer experiences," he says. “Citigroup’s management team has also built strong white label partnerships with household names in the airline, retail and financial services sectors over many years. This expertise, together with our commitment to deliver market leading products and services, provides an opportunity to grow with existing partners and add new partners.”

The deal includes a $7.9 billion mortgage book, $4.3 billion in unsecured lending, $9 billion in retail deposits, one million credit card customers and private wealth management operations.

The transactional and spending data unlocked by the deal is expected to grow in siginificance as NAB faces off competition from the country's well-established buy now, pay later competitors.

NAB in September launched an alternative to third party BNPL offerings with the release of an interest-free credit card. The NAB StraightUp Card provides access to staged credit limits up to a maximum of $3000 for a flat monthly fee of between $10-$20.

The sale does not include the technology component and will see NAB enter into a 30-month Transitional Services Agreement (TSA) with Citigroup to assist with integration. During this period, McEwan says NAB will invest in a new technology platform to support the combined unsecured lending business.