Lloyds Banking Group is offshoring some 300 IT roles to its suppliers, and cutting a further 100 IT positions, prompting outrage from trade unions.
The cuts are part of 1,600 UK redundancies planned across the company, and were announced as Royal Bank of Scotland said it was also cutting 460 jobs across its functions.
Lloyds is over 40 percent taxpayer owned, while RBS is over 80 percent publicly owned, following their bailouts during the financial crisis.
Lloyds said the 300 IT roles being offshored will be moved to its outsourcers in India. Other roles come from group operations, and its wholesale and insurance divisions.
The RBS cuts mainly affect its Bristol, Farnborough and Wimbledon sites.
David Fleming, national officer at trade union Unite, described the announcements as "brutal".
"Once more these banks are attacking some of their lowest paid staff to achieve cost savings. Today is yet another devastating day for bank workers as they witness these institutions pressing ahead with massive job cuts, without any consideration as to the consequences for these individuals, their families and the economy as a whole."
Lloyds Banking Group said in a statement that its policy "is always to use natural turnover and to redeploy people wherever possible to retain their expertise and knowledge within the group".
"Where it is necessary for employees to leave the company, it will look to achieve this by offering voluntary redundancy. Compulsory redundancies will always be a last resort," it added.
RBS said in a statement: "We are working hard to rebuild RBS in order to repay taxpayers for their support and having to cut jobs is the most difficult part of this process."