Today, the Partnership for Carbon Transparency (PACT) and Together for Sustainability (TfS) are publishing a new joint guide, co-authored by both initiatives, to help companies navigate methodological and technical differences in PCF calculation and exchange with confidence.

Product carbon footprints are only as useful as the trust placed in them. For companies operating across chemical value chains, that trust depends on a shared understanding of how emissions are measured, and what to do when the rulebook isn't identical on both sides of the conversation.

PACT and TfS have been working to align their PCF methodologies since 2021, and the two approaches are today largely compatible. However, a small number of methodological and technical differences remain. Without clear guidance, those differences create ambiguity, slow down procurement decisions, and reduce trust in emissions data.  

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Who it is for

"Navigating Methodological and Technical Differences between PACT and TfS" is designed for companies on both sides of a PCF exchange.

• If you're a PCF builder calculating under the TfS Guideline and want to ensure PACT alignment, the guide tells you exactly where the two approaches diverge, what action is needed, and where flexibility exists.  

• If you're a PCF recipient assessing a supplier's TfS-calculated PCF, it gives you the right questions to ask, the formulas to apply, and the criteria to interpret differences confidently.

Covering ten areas across calculation methodology, data integrity, verification, and the data model, the guide translates real differences into practical solutions — conversion formulas, practical thresholds, and clear supplier questions, all in one place.

Why it matters

Corporate climate commitments increasingly depend on Scope 3 data, and PCFs are its building blocks. As regulatory expectations tighten, ambiguity in how emissions are calculated and exchanged is a liability no company can afford.

PACT provides the infrastructure on which credible value chain decarbonization depends. This guide is a concrete expression of what it looks like when sector-specific approaches like TfS build on that foundation, in service of the companies and climate goals they share.  

The remaining differences between PACT and TfS are well understood and manageable. This guide shows exactly how to overcome them in practice. Because consistent, credible carbon data isn't just good practice. It's how decarbonization actually happens.

Download the guide

Feedback on the guide's technical accuracy and usefulness is welcome at pact@wbcsd.org

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