External assurance can greatly enhance the credibility of sustainability disclosures because it helps to build confidence in the reported information and build relationships of trust. Investors, rating agencies and other analysts increasingly look for assurance when making investment and rating decisions based on sustainability performance. The assurance typically involves careful planning, followed by work to look at the scope of reporting, interviews with management, and an early draft review of findings. Assurance requires exactly what areas the assurer has assured to be identified in the content index. It removes the veil over how much of a report is actually assured. It should be noted that in a reporting context an assurance is not the same as an audit and the people that carry out each should be quite separate and independent. A range of different providers including accountants and specialist consultants can provide external assurance or verification of sustainability reports.