Tax-avoidance activists have targeted Barclays Bank, staging a sit-in at a branch in central London and protests in other parts of the UK.
About 60 demonstrators from the group UK Uncut entered a branch on Tottenham Court Road and another 50 gathered outside the Piccadilly Circus branch.
There were also protests elsewhere in London, plus Manchester and Cambridge.
A Barclays spokeswoman said: "We comply with taxation laws in the UK and in all the countries where we do business."
The bank "takes its responsibilities as a corporate citizen very seriously", she added.
'Not really acceptable'
The UK Uncut protesters said they wanted to "open up" the banks, occupy them and transform them into "something people will need but will be cut".
Those at Barclays at Piccadilly Circus chanted "books not bonuses" and made an impromptu "library" outside the building.
Protesters also set up a live comedy show and a mothers' breakfast club at different branches of the bank in the capital.
"In 2010 the group paid over £2.8bn in taxes in the UK and £6.1bn globally," the spokeswoman said.
"We have signed up to the UK government's code of practice on taxation, which is very clear on the obligations it places on banks to ensure they manage their tax affairs properly."
But protesters in central London claimed people were angry at the refusal of Barclays' chief executive, Bob Diamond, to apologise for the banks' role in the economic crisis.
"We are hoping to very peacefully and legally send a big message to Barclays that paying 1% corporation tax is not really acceptable," said a UK Uncut spokesman.
"We are tired of us paying into the public sector and seeing our public sector decimated while corporations are effectively getting away with theft."
After about 30 minutes of public protest at Piccadilly Circus, police officers intervened to ask the activists to move on.
Demonstrators also gathered at Barclays branches in Brixton, Dalston, Elephant and Castle, and Lewisham in London, plus an RBS branch off Regent Street in central London.
The Metropolitan Police said no arrests were made during the protests.