Chamber chief executive John Christie said he had "certainly heard from more and more businesses that did not realise the seriousness of the implications" of the changes.
Businesses were having to rethink the way they were doing things, courier drivers were complaining, and "the effects ripple out", he said.
Under the new regime, parking fees increased in the central city, 153 new pay-and-display machines were installed, and the number of free time-restricted parks was reduced.
The loss of the time-restricted free parks was the biggest issue, Mr Christie said.
He expected the council to be reluctant to go "back to the drawing board", but the committee could "work with what's there" to solve the problems.
Planning and environment committee chairman Michael Guest said he hoped the informal committee would be able to listen to concerns of those who did not think they had been properly consulted.
"There are certainly issues to resolve on a case-by-case basis."
