When a company confronts reporting of their environmental, social, and governance (ESG) metrics for the first time, an aspect of the process looms large in the background: the need to seek assurance.

Rules like the European Union’s Corporate Sustainability Reporting Directive and Securities and Exchange Commission’s climate-related disclosure proposal each carry requirements that companies receive a level of assurance from a third-party source on the information being reported. That assurance mandate might be defined as the more thorough “reasonable” or the less rigorous “limited,” depending on the regulation.

Either way, it’s important companies exercise patience when determining when to begin an assurance engagement, experts discussed during a session at Compliance Week’s virtual ESG Summit on Tuesday. The process will likely take at least 12 months from start to finish and each step along the way is crucial.