The implementaiton of business continuity plans meant it was business as usual for most companies following the terrorist attacks in London.
Steve Mellish, head of business continuity at Sainsbury's, and chairman of the Business Continuity Institute, said the retailer's business continuity team sprang into action to oversee operations.
"Text messaging was more effective for the continuity team, and our staff freephone number worked very effectively," he said.
"Staff had the numbers on business continuity cards - and information was updated throughout the day. Our IT was unaffected because it is outside central London,"he said.
In the City, the London Stock Exchange said it evacuated some staff, and some orders were deleted, but the trading system carried on without any technical problems.
London Clearing House, LCH.Clearnet, was evacuated and operations resumed at an alternative site, after the series of explosions on the London transport network.
Some financial firms, including Swiss banking giant UBS, evacuated their City buildings and switched operations abroad, with no impact on trading.
Other City banks including Goldman Sachs, JP Morgan Chase, Deutsche Bank and Merrill Lynch said the blasts had no impact on their businesses.
Lorraine Darke, a spokeswoman for the Business Continuity Institute, said its members were "out there working flat out, and have not reported back. The only problems people have experienced have been with pagers and mobiles".