Lloyds Banking Group is cutting 3,000 jobs and shutting 200 branches as the lender braces for a cut in interest rates following Britain's decision to quit the European Union.
The part state-backed bank said a cost-cutting programme announced in 2014 will be extended and the "expected lower for longer interest rate environment" will see the new cuts come into effect by the end of 2017.
The Bank of England is widely expected to cut interest rates from 0.5% to 0.25% next week as the fallout from the Brexit vote intensifies.
Lloyds is targeting £1.4 billion in cost savings by the end of next year.
The bank made the announcement alongside results for the first half of the year, which saw statutory profits more than double to £2.5 billion, but the lender warned that Brexit could have an adverse impact on its future performance.
"Given the uncertainty, it is too early to determine the impact on our formal longer term guidance at this stage. However, while the business will remain highly capital generative, it is possible that this capital generation may be somewhat lower in future years than previously guided," the bank said.