There is a growing realisation that the current upward trend in levels of disclosure of social, ethical and environmental performance by corporations and other organisations is not being accompanied by simultaneous greater levels of public trust. Low levels of confidence in the information communicated in public reporting is probably undermining the impetus for this disclosure. This article suggests that this credibility gap can be narrowed through the use of third party independent assurance. However, this is not an unqualified panacea. Much (...) verification and assurance practice itself has to date been of questionable robustness, reliability and consistency, and has been framed by financial assurance models that are inadequate for the broader, qualitative dimensions of social, ethical and environmental performance. The paper argues that there is need for a universal standard for the provision of assurance of social, ethical and environmental reporting, and indeed for the credibility of the assurance providers themselves. The new AA1000S Assurance Standard, developed by the Institute of Social and Ethical AccountAbility, offers an approach and a tool for addressing these gaps. (shrink)