The Pension Levy introduced this month could hit certain types of companies harder than others, experts at Oxford-based finance firm Grant Thornton warn that partnerships and limited liability partnerships (LLPs) are particularly at risk. The levy is being introduced in a bid to build up a central pot of funding to meet pension scheme liabilities in the event of a company failing.

The amount is partly based on a financial risk assessment of individual schemes.

Grant Thornton partner Stephen Dexter believes partnerships and LLPs may be unfairly disadvantaged, if the risk assessment is based on incomplete or inaccurately interpreted information.

He said: "With the recent changes in the Pensions Act 2004, large partnerships and LLPs, such as law firms or construction and property professionals with defined benefit pension schemes, could be facing a higher bill for their Pension Levy than may be properly due from them.

"For example, the financial risk assessment may be incorrectly based on the business being a new start-up, because of a recent conversion to LLP status from partnership, with only one year's accounts having been filed at Companies House.

"If the facts of its financial history are properly explained to the risk assessor, the firm may be able to achieve a considerable saving in the levy."

The levy will come into effect from this month, following a consultation document in July 2005 and updates in October and December 2005.

The levy is payable annually and is a pension scheme liability. These levies will replace an initial levy which was modest by comparison when it first kicked in during the spring of 2005.

The 2006 levy, which is understood to relate to the year to March 31, 2007, is expected to be invoiced to scheme trustees in the late summer. Schemes will have 28 days to pay.

Mr Dexter said: "Partnerships and LLPs with defined benefit/final salary schemes should check their Pension Levy assessment is based on the firm's full historical financial record, and that they have provided all the information required.

"If they don't do that, they may well end up paying more Pension Levy than they need."