Jointly developed by IOM and the United Nations Office on Drugs and Crime, this guidance manual aims to support the efforts of governments and other stakeholders in improving data collection, management, sharing and use, so that more high-quality data can be leveraged to inform policy and programming. While the manual will be useful for all stakeholders dealing with administrative data, it specifically targets central government agencies or other organizations with a coordinating role at the national level that uses administrative data on trafficking in persons (TIP) from multiple sources to produce evidence in addressing TIP. These can be national rapporteur’s offices, ministries, agencies coordinating the national referral mechanism or national statistical offices, among others. The manual outlines useful considerations, describes the pitfalls to avoid, lists best practices and gives concrete examples to help establish (or improve) all data-related processes for national TIP administrative data. Importantly, it also provides direction on how to use the working version of the new International Classification Standard for Administrative Data on Trafficking in Persons, most effectively ICS-TIP. The ICS-TIP, the companion publication to this manual, establishes a new model of classification for key indicators related to TIP administrative data.