This document defines the functional and performance requirements and associated tests for Galileo timing receivers. The approach for this document is that of a performance based, meaning that no specific algorithm implementation is required. Instead, performance requirements are defined together with a corresponding test suite for verification. The subject of this document is the Galileo chipset. Other sensors and/or additional processing that a higher synchronization Unit can implement on top of the Galileo chipset are not the subject of this document. This document covers the following aspects related to Galileo timing receivers: GNSS constellations and frequencies processed: Galileo Dual-Frequency. Other modes are optional, as explained below; time scales, including Galileo System Time and Universal Time Coordinate; Services Levels, this document covers the 2 levels of Service for GST and for UTC to be provided by Galileo Time Service in the first place. The document also anticipates a third Service Level to be provided in the future, for which an update of the document will be needed; user dynamics: fixed users, defined as static users with precise knowledge of the antenna position, is the baseline mode; processing of Timing Service Message disseminated by the Galileo System; local timing integrity barriers: As a minimum, Time Receiver Autonomous Integrity Monitoring processing (T-RAIM); robustness to interferences; Galileo Open Service Navigation Message Authentication processing; robustness to multipath. This document does not cover the processing of GPS constellation but this does not preclude Manufacturers to implement GPS processing within the Galileo timing receivers, even if not addressed in this document. The use of other GNSS constellations is not forbidden by this document but the requirements and tests are defined considering Galileo-only, including those related to the integrity of the timing solution. Single-Frequency modes are not covered by this document. This does not preclude manufacturers to implement single-frequency modes within the Galileo timing receivers, even if not addressed in this document, as a back-up of the nominal Dual-Frequency mode, and reversion mechanisms. It is important to remark that the integrity of the timing solution is only specified for Galileo Dual-Frequency mode. The Galileo timing receivers addresses only users operating in static conditions. Moving users are not considered as part of this document. On top of the functional requirements, performance requirements are defined in this document in terms of different key performance indicators such as: accuracy, availability and integrity requirements; local barriers, T-RAIM performances. This document also provides the verification matrix and defines the test suite to verify the most fundamental requirements of the Galileo timing receivers. Finally, this document provides a section dedicated to guidelines for the installation and maintenance of the Galileo timing receivers. This is a comprehensive section, including provisions for the antenna, cabling and receiver installation, as well as the calibration of time delays.