Each party establishes a Contact Network of experts within their own organisation or region in order to ensure that, in the discussions, they reflect the views and policies of the co-sponsor they represent. The way in which this network operates differs according to the administrative structure of the party concerned.

For each of the technical topics which have been selected for harmonisation in the first phase of activities, the SC appointed a Working Group to review the differences in requirements between the three regions and develop scientific consensus required to reconcile those differences. Working groups do not have a fixed "membership" but each of the six parties have nominated a Topic Leader (and, frequently, a Deputy Topic Leader) as the contact for the topic. The Observers to ICH, the Pharmacopoeial authorities and representatives from the self-medication industry and the generic industry have been invited to participate in various working groups.

There are several different types of ICH working groups that can be identified:

  • EWG: Expert Working Group is charged with developing a harmonised guideline that meets the objectives in the Concept Paper and Business Plan.
  • IWG: Implementation Working Group is tasked to develop Q&As to facilitate implementation of existing guidelines.
  • Informal Working Group: Is formed prior to any official ICH harmonisation activity with the objectives of developing/finalizing a Concept Paper, as well as developing a Business Plan.
  • Discussion Group: Is a group established to discuss specific scientific considerations or views i.e. Gene Therapy Discussion Group (GTDG), and ICH & Women Discussion Group.

One of the working principles agreed by the SC was that an EWG could only meet in its official ICH capacity if there was at least one nominated expert from each of the six ICH co-sponsors.