The Financial Reporting Council has warned that there is a general consensus from companies that the market is immature and does not deliver consistent high quality assurance of sustainability reporting.

There was criticism of the high costs from the direct fees payable to the assurance providers and the costs associated with developing company systems, processes and controls underpinning disclosures. 

The FRC said it had been told the price of assurance can vary significantly, from 5% to 30% of the statutory audit fee. 

It also warned that there may be greater burdens for small/mid-cap companies that have fewer resources available to dedicate to obtaining assurance.