The banking group will acquire approximately £2.5 billion of gross customer assets, comprising £1.4bn of unsecured personal loans and £1.1bn of credit cards balances, together with approximately £2.6bn of customer deposits.

As part of the transaction NatWest also expects to add around one million customer accounts.

The deal, excluding ATMs, insurance, and travel money, marks the first major move by NatWest’s new CEO, Paul Thwaite, and further accelerates the supermarket sector’s retreat from financial services.

Mr Thwaite said: “Following today’s announcement, we look forward to welcoming new customers to NatWest Group, where they will benefit from our expertise and award-winning digital banking offering.

“This transaction is a great opportunity to accelerate the growth of our retail banking business at attractive returns, in line with our strategic priorities. As well as a complementary customer base, the transaction is expected to add scale to our credit card and unsecured personal lending business within existing risk appetite.

“NatWest Group has a strong track record of successful integration, and we are focussed on ensuring a smooth transition for customers.”

The current figures are estimates as the deal is expected to close on 31 March 2025. NatWest Group will receive an agreed £125 million consideration payment from Sainsbury’s upon completion.

Simon Roberts, Sainsbury’s CEO, said: “I am pleased to be announcing this news today. NatWest’s values and customer focus are a close fit with ours and as one of the UK’s leading banks, NatWest’s scale and financial services expertise will ensure our existing financial services customers continue to be well looked after.

“There will be no immediate change for our bank customers as a result of this announcement.

“Today’s news means we will focus all our time and resources going forward on growing our core retail business, delivering great quality and value, week in week out.”