London companies support the congestion charge, according to a survey of 300 big firms.
Three-quarters of those questioned by business organisation London First said the charge was working while 3 per cent dissented.
A minority - 5 per cent - felt the scheme had a negative effect on business performance, but they were outnumbered by the 65 per cent who reported no change. The remaining 30 per cent said it was good for business.
London First transport director Julia Lalla-Maharajh said the scheme appeared to have got off to a good start.