Why was it developed?


There are competing approaches and concepts for "Net Zero" governance, and the ISO Net Zero Guidelines (IWA 42) provide a common reference for collective efforts, offering a global basis for harmonizing, understanding, and planning for net zero at state, regional, city and organizational level.

This common reference provides:

  • Clear definition of “net zero” and related terms (greenhouse gas removals, offsetting, value chain, etc).
  • Clarity in the differences in scope between direct emissions, indirect emissions from purchased energy, and other indirect emissions arising from an organization’s activities.
  • Better alignment of voluntary initiatives and adoption of standard, policies and national and international regulation.
  • High-level principles for policy makers and organizations who want to achieve climate neutrality. 
  • Actionable guidance on getting there as soon as possible, not just by 2050. 

Launch of the ISO Net Zero Guidelines IWA 42:2022 at COP27, featuring Scott Steedman, Director-General Standards at BSI.
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Delivering credibility 

More than 1,200 experts from over 100 countries contributed to make the ISO Net Zero Guidelines (IWA 42), which build on the momentum of existing voluntary initiatives. The ISO Net Zero Guidelines (IWA 42) will be reviewed in 2025, three years after its publication, and can be further processed to become a Publicly Available Specification (PAS), or an International Standard (ISO).

While ISO Net Zero Guidelines (IWA 42) is a set of guidelines and not a standard on which to provide assurance, the BSI Net Zero Pathway is based on these guidelines and our long-standing history of delivering credible assurance claims. As such, organizations will be certified to the BSI Net Zero Pathway based on these guidelines.

As ISO Net Zero Guidelines (IWA 42) is a guidance document it is not possible to become certified to ISO Net Zero Guidelines (IWA 42) outside of the BSI Net Zero Pathway.


Self assessment questionnaire.

ISO Net Zero Guidelines (IWA 42) How ready are you? 
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ISO Net Zero Guidelines (IWA 42) Podcast 

Discover ISO Net Zero Guidelines (IWA 42) in 10 minutes, a series from The Standards Show, the podcast that brings you the stories behind the standards.
Listen here