One Standard To Rule Them All? What The GHG Protocol–ISO Unification Means For Organizations And Carbon Management Software

On July 29, 2026, the GHG Protocol and the International Organization for Standardization (ISO) confirmed plans to merge their standards into a single, co-branded corporate accounting standard, folding GHG Protocol's Scope 1, 2 and 3 and Actions and Market Instruments guidance together with ISO 14064-1. The partnership was announced in September 2025, and the open question since then has been timing. That's now been answered: consultation is set for Q2 2027, with a final standard targeted for Q4 2028. Current standards stay fully in effect until then, meaning this year's reporting is unaffected.

This is the first overhaul of the GHG Protocol Corporate Standard since 2001, addressing fragmentation that has shaped carbon accounting for decades. Organizations have long navigated two systems – GHG Protocol's Scope 1, 2 and 3 framework and ISO 14064-1 – and verifiers, regulators and platforms often build around one or the other, leaving multinationals to reconcile both. ISO's version organizes emissions into six categories rather than three, and stays more flexible about how firms draw boundaries around indirect emissions. Apart from branding, that structural gap is part of what the merged standard has to resolve.

Furthermore, GHG Protocol's own Scope 2 revision, already underway before this announcement, is still working through roughly 1,100 comments from 56 countries on proposed electricity accounting changes, centred on whether renewable energy purchases need to be matched hourly and whether that electricity has to plausibly reach the sites consuming it. That revision, and the ongoing Scope 3 update, is now being timed to align with the broader ISO integration rather than proceeding on its own schedule. A parallel product carbon footprint standard, built on ISO 14067 and GHG Protocol's Product Life Cycle Accounting and Reporting Standard, is tracking towards a public consultation draft around late 2026.

For businesses, near-term impact is small, but in the long term the collaboration will mean fewer duplicate audits, one methodology to train teams on, and no need to defend two footprints to two audiences. One caveat is that IFRS S2, the ESRS and the CSRD reference the existing GHG Protocol standard by name, so a revised, unified standard doesn't automatically inherit that regulatory status. The ISSB has welcomed the direction, but how and when a new standard actually gets folded into disclosure rules that already reference the old one isn't yet clear, and that gap could leave organizations following an updated methodology that regulators haven't yet formally recognized.

For tech providers, the pre-existing Scope 2 revision is where technical change could land soonest, since it touches live calculation questions – such as hourly matching and deliverability – that directly affect how platforms compute Scope 2 numbers today. The PCF standard is the other development to track, given its shorter timeline and its direct bearing on allocation and boundary choices that PCF and LCA tools build into their calculation logic.

To learn more about vendors offering carbon management software, read Green Quadrant: Enterprise Carbon Management Software (2026).