This document provides guidance on the relationship between ISO/IEC 20000–1 and a commonly used service management framework, ITIL 4. It can be used by any organization or person wishing to understand how ITIL can be used with ISO/IEC 20000–1, including: a) an organization that has claimed or demonstrated or intends to claim or demonstrate conformity to the requirements specified in ISO/IEC 20000–1 and is seeking guidance on the use of ITIL to establish and improve an SMS and the services; b) an organization that already uses ITIL and is seeking guidance on how ITIL can be used to support efforts to demonstrate conformity to the requirements specified in ISO/IEC 20000–1; c) an assessor or auditor who wishes to understand the use of ITIL as a support in achieving the requirements specified in ISO/IEC 20000–1. Clause 4 describes how ITIL can support the demonstration of conformity to ISO/IEC 20000–1. Clause 5 correlates the ITIL documents to requirements in ISO/IEC 20000–1. The tables in Annex A correlate terms and clauses in ISO/IEC 20000–1 to ITIL and vice versa; the tables in Annex B correlate clauses in ISO/IEC 20000-1 to the ITIL 4 publications and vice versa.