Complementarity is an approach to humanitarian collaboration based on the recognition that all actors play a role in enabling effective humanitarian responses. A more complementary humanitarian system is essential to deliver faster, fairer, more efficient, sustainable and accountable responses, particularly in a context of shrinking resources and growing needs. At its core, complementarity requires actors to build on comparative advantages and work toward shared outcomes. Given the ongoing changes in the humanitarian landscape, the need for a collective approach, which leverages the strengths of diverse actors, will be paramount for maximizing humanitarian impact moving forward.

In late 2025, the IASC Principles requested that the Humanitarian Working Group (HWG) prepare a paper on complementarity in the humanitarian sector, examining how local actors, INGOs, the UN, and other actors can better complement one another in different contexts. The paper’s aim is to enhance complementarity among humanitarian actors by capitalizing on their unique strengths, promoting localization, and ensuring principled, accountable, and impactful collective action, while identifying barriers and presenting recommendations. The paper will articulate a set of principles supported by practical guidance, which can be adapted to various contexts.

In this HNPW session, the HWG seeks to hear perspectives on complementarity generally as well as the specific approach in order to inform the development of the paper. The session will provide an opportunity for participants from various backgrounds to provide their viewpoints on the opportunities and challenges of operationalizing complementarity and to discuss pathways forward for strengthening collaboration across diverse actors.