Companies are being forced to pay out thousands of pounds on protected commercial claims, then claim the money back from the Policyholders' Protection Board (PPB).
Companies insured by Independent Insurance have had to cover commercial claims payouts following the insurer's collapse.
There is no set time period in which the PPB must refund their money. This leaves some small companies in financial difficulties.
Thomas Sagar Insurances director John Meadows said one of his clients, a south coast quarry, was informed last week it would have to pay out more than £50,000 on an employers' liability (EL) claim.
“It will just about be able to cover it, but it will be a big dent to its finances, because it's not a big firm,” he said.
“The worst thing is that it came out of the blue, so there was no way they could budget for it.”
Wilby associate director Mark Stud-holme said he had several clients facing the same situation.
“Because they're long-tail claims, they take months and months to negotiate, but now we're getting letters saying the claims are ready for settlement,” he said.
“We're notifying clients of the procedure to follow, but we were in the dark about it ourselves for some time.”
A spokesman for the PPB said the speed of the refund varied from case to case. “There's no set figure,” he said.
By the beginning of this week, the PPB had paid out £7.8m, a jump of about £4m on recent figures because of the large number of return of premium payments made to Carole Nash customers.
The spokesman said the PPB had made no move to set a new levy for insurers, although it is one of seven compensation schemes due to merge on November 30 into the new Financial Services Compensation Scheme.