Marsh and Willis will be expected to pay a tariff for use of the Kinnect system at Lloyd's as the new Kinnect board works out tariff levels for the market.
Kinnect chief executive Toby Davies said: "As we move away from Lloyd's we will move away from Lloyd's funding and everyone will be charged. That includes Marsh and Willis."
Davies ruled out lowering the charges for Marsh and Willis despite their being instrumental in Kinnect's development.
He anticipated that tariffs would be charged per size of risk processed to allow smaller brokers to make use of the platform.
"We will be looking at how we set a tariff to encourage new people to sign up."
Sources said the charges could be "hundreds of pounds" per risk, but Davies would not confirm a figure.
He said within five years Kinnect expected to capture 80% of the market and that more partner companies were expected to be named within weeks.
' Criticisms that Kinnect will not be able to bind online were rebuffed by Marsh managing director Jonathan Prinn at a demonstration of the system in the Lloyd's building on Friday.
But a market source at the presentation, said: "What we saw was how Kinnect could bind online, not that it does bind online.
"There is no legal framework built into the platform and no electronic framework to produce an electronic signature between underwriter and broker.
"This makes it less secure than using traditional paper."