This document has been published by the TSO to provide clarity on the electromagnetic transient (EMT) modelling requirements for High Voltage Direct Current (HVDC) systems in Ireland, as specified in Grid Code clause PC.A8 (Modelling Requirements for Users) [1.], in compliance with European legislation EU 2016/1447 reflected in the Network Code for High Voltage Direct Current Connections (HVDC) [2.]). The contents of this document are also in alignment with the recommended amendments to the existing HVDC Network Code submitted by ACER to the European Commission in December 2024 (HVDC 2.0) [5.], and expected to be approved in 2026.