A bank closed a historic branch office on Friday after it decided West Norwood was too dangerous a place to operate.
The shock move, which has deeply angered residents, follows an attack on staff in August, the seventh such incident in the past 11 years.
The closure of the NatWest branch, in Norwood Road, which has been operating since 1896, has angered customers who will have to travel elsewhere and has raised questions about the future of the high street.
A NatWest spokesman said the bank had taken the difficult decision to close the bank in response to security threats.
The spokesman said: "The attack in August was the seventh such incident in the last 11 years and the decision to close was made in the interests of the safety of our customers, staff and the local community."
The nearest branch is now in Streatham High Road and there are other branches are in Brixton and Clapham.
Councillor John Whelan, who represents Thurlow Park ward, said residents were unhappy about the branch closing without consultation.
Coun Whelan said: "It’s really bad news. It’s pretty depressing from the point of view of the revival of the high street and doesn’t seem like a huge vote of confidence."
"Customers have told me they will be inconvenienced."
Dulwich and West Norwood MP Tessa Jowell said: "This is a body blow to local residents and businesses in West Norwood.
"I am concerned at the speed of the decision and the fact that NatWest appears not to have looked at further safety measures to protect its staff and customers."
Stavros Tsoukkas, owner of the nearby Electric Cafe, said: "It's a disaster for us because it's the bank on our doorstep.
"It's hard enough to run a business without having to trek to Streatham or Brixton."
Pat Burford, from David Anthony's hairdressers opposite the closed up branch, described the closure without any notice as 'disgusting'.
Ms Burford said: "I think it is terrible. I know they had a lot of robberies but why didn't they do something about it to make it less accessible.
"A lot of people around here are elderly and it's awkward for them to get to Streatham or Brixton."
NatWest customer Harley Faggetter said police needed to patrol the high street to make the area safer.
Mr Faggetter said: "I'm just saddened by the situation in West Norwood when the rampant gang violence and behaviour has got to a stage when they can force out a bank."