Johnston Carmichael, Scotland's biggest independent accountants and with turnover of more than £33million, say many businesses who were mis-sold interest rate hedging products (IRHPs) are in danger of losing out due to lack of clarity over who is eligible for compensation.
Susie Walker, head of tax at Johnston Carmichael, says the Financial Conduct Authority (FCA) guidance about which businesses can make claims is "woolly" and confusing to many small companies which have been affected by IRHPs.
The FCA has said banks are on track to complete their review of 19,000 cases of IRHP mis-selling by the end of this month.
But a further 11,000 cases have been ruled out of the review due to firms being "sophisticated", according to certain criteria set by the FCA, though not enshrined in any legislation, which include such things as turnover and staffing levels.
Ms Walker said: "The sophistication test is broadly assessed on whether at the time of the sale the customer, irrespective of the size of the business, had the necessary experience and knowledge to understand the service to be provided, its level of complexity and the risks involved.
"These criteria are woolly at best, as the banks who are co-operating with the review are often not in a position to determine who is or isn't 'sophisticated' as a customer."
The tax expert went on to say Johnston Carmichael has worked with several clients which have successfully challenged the criteria. She said: "The banks have had to employ over 2,800 people on the review of lending files and have gone through over five million documents.
"If the people reviewing a company's file have concluded it was a 'sophisticated' customer, it will have been excluded from the review and with no communication from its bank about any possibility of compensation.
"Many businesses which were sold IRHPs are potentially losing out because they are not being invited to make a claim. We have worked with a number of clients who were initially excluded, including one which was ultimately paid almost £500,000 compensation after they challenged the bank."
Ms Walker suggested it is likely the strict criteria will eventually lead to further problems and concluded: "The FCA is opening the door to a flood of complaints ....which could see this whole situation prolonged.
"My advice is for affected businesses to contact their bank even if they've not been invited to join the review for compensation and to explore whether there is further scope to press for a claim. The starting point is to ask for the basis on which they have been assessed as 'sophisticated'."
The accountancy firm backs up the objections of campaign group Bully Banks, whose chairman Jeremy Roe says garage owners, manufacturers, publicans, care- home owners and hoteliers are typical of those excluded from the scheme.
He said: "To exclude 39 per cent of the SMEs mis-sold these products is not justice - it is merely another consequence of the banks' power when dealing with the financial regulator."
The redress offered to the "sophisticated" SMEs is limited to an alternative hedging product or swap. Mr Roe said: " Given that the swap is, in the vast majority of cases, a wholly unsuitable product for an SME, this is damage limitation agreed between the FCA and the banks."
Firms ruled out of the review have no option but to threaten legal action against their bank.
Specialist lawyer Simon Jaquiss, at QA Legal, commented: "There is mounting evidence that legal action is not the best route for swaps claimants." He said three cases brought by SMEs against RBS, one of them in Scotland, had been defeated in the past year.
"This sends out a strong signal that it will take a Herculean effort to defeat the banks," Mr Jaquiss said.
"The key lesson is that the legal route is fraught with risk, entails significant cost and can be a protracted and stressful experience. Regardless, many business groups continue to advise members to seek legal help rather than going to treasury experts."
The banks have up to now set aside provisions of over £3billion for the mis-selling, and have so far paid out almost £800million, with a deadline for completing the review by the end of this month. But an FCA spokesman said: "A large part of this provision covers the costs of having to get out of the corresponding "back-to-back" IRHP contracts entered by the banks.
"This cost should be seen as the value of the payments that customers would have continued to make to the banks under their IRHP agreements had the IRHP review not been put in place. In addition, the cost of undertaking the review is also taken into account."