The boss of taxpayer-backed NatWest has reassured customers that "a corner has been turned" as it wades through a backlog of transactions following an IT meltdown.
Stephen Hester, chief executive of NatWest parent RBS Group, said senior executives would face "proper accountability" following the fiasco, which is in its seventh day.
Some customers have been unable to view an up-to-date balance, payments such as direct debits for bills have not been made and some wages have not been received following a software update last Tuesday.
Mr Hester said: "We're well on the road to recovery. Fingers crossed all the bugs have been got out but we feel a corner has been turned."
Some 1,200 main NatWest and RBS branches will be open from 8am to 6pm for the rest of the week after staying open late last week and opening for the first ever time on a Sunday.
RBS, which is 80% state-owned, potentially faces an overtime and compensation bill running into hundreds of millions of pounds, according to analyst Gary Greenwood at Shore Capital.
The bank has promised that any overdraft fees or charges on current accounts incurred by customers will be waived or refunded and has said it will work directly with credit agencies to ensure no-one's credit score is affected.
Consumer champion Which? said customers will not automatically be entitled to any additional compensation for the disruption, but the Financial Ombudsman Service (FOS) has advised people to keep a record of how they have been affected in case they need to complain later on.
Asked if he had considered his own position following the debacle, Mr Hester said: "The most important thing that I or anyone at RBS can do is to put this right. There's plenty of time afterwards to say why did it happen, how do we stop it happening, what's the accountability, all of those things can and will happen but right now, we're putting it right."