The WHO/IWA document <I>A practical guide to auditing water safety plans</I> provides guidance on developing and implementing a WSP auditing scheme, covering such topics as the aim and role of auditing, auditor training and certification, audit criteria, audit timing and frequency and audit reporting. The guidance document includes examples, tips, tools and case studies from more than a dozen low-, middle-, and high-income countries, and it serves as a practical resource for policy makers, government bodies responsible for drinking-water regulation or surveillance and water suppliers implementing WSPs.