Article 6 Insights

Article 6 of the Paris Agreement is increasingly shaping the future architecture of global carbon markets. While it remains primarily a government‑to‑government and compliance‑focused mechanism, its sphere of influence is expanding across technical standards, compliance‑adjacent demand (notably CORSIA), and the availability of high‑integrity supply.

Importantly for corporates, Article 6 does not immediately change how voluntary climate action is undertaken today. Alignment is not mandatory for corporate use of carbon credits, and existing voluntary frameworks remain valid. However, as Paris Agreement integration continues to build, with compliance and voluntary markets becoming more interconnected, understanding the direction of travel is becoming strategically important.

At Climate Impact Partners, we are actively plugged into Article 6 market developments  - across policy, supply pipelines, and demand signals - to ensure clients remain well positioned as this landscape evolves.

Here we provide a refresher on Article 6, explore how the latest updates impact credit portfolios, and when alignment with Article 6 is optional or obligatory.

Article 6 refresher

Article 6 of the 2015 Paris Agreement establishes the rules for international carbon market cooperation. It sets common accounting standards for emissions reductions and CO₂ removals, enabling countries to trade mitigation outcomes while preventing double counting. By providing a robust global framework, Article 6 aims to mobilize climate finance at scale and help countries meet their climate targets more cost-effectively.

• Article 6.2 provides a framework for bilateral trading of credits, known as Internationally Transferred Mitigation Outcomes (ITMOs) to meet countries’ nationally determined contributions (NDCs). The framework is decentralized, relying on bilateral agreements between countries to set quality rules, and on national systems involving Letters of Authorization (LoAs) issued by the host country, committing to apply Corresponding Adjustments (CAs) to its national emissions inventory.
• Article 6.4 is now known as the Paris Agreement Crediting Mechanism (PACM). This centralized certification standard will replace its predecessor, the Clean Development Mechanism (CDM). It aims to build on lessons from the CDM and align with the raised climate ambition of the Paris Agreement.With UN governance and standardized methodologies, it will provide a mechanism to enable the trading of high-integrity credits, for both compliance and voluntary use.
  

MSCI projects Article 6 could account for 50% of global carbon credit demand by 2040. However, this demand remains slow to materialize as governments work out how to incorporate carbon credits in their Paris Agreement targets, and CORSIA is constrained by regulatory ambiguity and fragmented supply.

Where do Corresponding Adjustments come in?

Corresponding Adjustments (CAs) are an accounting measure to ensure there is no double counting between a host and the country acquiring ITMOs. They work by ensuring the host country adds back the mitigation outcome (MO) into its emissions inventory, and the buyer country subtracts it.

This mechanism enables transparency and accountability, allowing countries to track progress against their climate goals confidently.

CAs are mandatory when a credit is used towards a country’s NDC or for complying with the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), or toward some domestic systems, for example Singapore’s carbon tax.

When eligible credits have been authorized by a host country and correspondingly adjusted, they are referred to as Correspondingly Adjusted Credits.

While CAs are most relevant in the context of NDCs and national climate action, many corporates are increasingly considering whether CAs are required for corporate climate claims made using carbon credits.

When it comes to voluntary frameworks, as of today, none require Correspondingly Adjusted Credits.

Note: Gold Standard announced that as of 1 January 2026, its requirements and methodologies will be aligned with the Paris Agreement. This means delivering methodologies that align with 1.5°C trajectories and decarbonization technologies, increased ambition, robust quantification through impact reporting and rigorous accounting standards. This is not to be confused with the Paris Agreement Crediting Mechanism – these methodologies do not currently form part of PACM. 

CORSIA and Article 6

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is the first global market-based scheme that applies to a sector. It means airlines and aircraft operators must offset any growth in CO₂ emissions above 85% of 2019 levels.

CORSIA is currently in Phase 1 (2024-26), with 130 countries participating. From 2027, all countries will be obliged to participate. Airlines flying between participating countries are required to comply with CORSIA, or potentially face penalties. Under CORSIA, credits used by airlines must:

• Be authorized by the host country
• Be supported by a formal Letter of Authorization (LoA)
• Receive a CA under Article 6 of the Paris Agreement

Under CORSIA, aircraft operators can also lower their offsetting requirements by using Sustainable Aviation Fuel (SAF).

Article 6 progress made at COP30

The texts for Article 6.2 and 6.4 were finalized at COP29 in 2024, marking a pivotal moment for global carbon markets. This paved the way for further progress at COP30 in Belém, Brazil. Here, Article 6 dominated discussions as a cornerstone for scaling climate finance and focused on removing blockers to allow full implementation.

During COP30, the International Chamber of Commerce (ICC), representing over 45 million companies worldwide, called for a strengthening of governance under Article 6 to create an environment for business engagement to flourish.

Inside the negotiating rooms, parties focused on implementation oversight and means to avoid double counting. Reporting inconsistencies were flagged during the first ITMO transfers, however these are expected to improve with upcoming Biennial Transparency Reports due at the end of 2026.

Outside the rooms, countries continued to form alliances and frameworks to operationalize Article 6, signaling that the mechanism is moving from concept to reality.

Article 6 in 2026 and beyond

Today, the real supply of Article 6-compliant CACs remains limited, due to slow government authorizations and registry readiness. Pricing varies widely, and uncertainty remains on how quickly supply can scale.

However, the carbon market overall has entered 2026 with renewed momentum. Integrity standards are rising, supply is evolving, and updates to leading frameworks are formalizing the role of carbon credits in corporate net‑zero strategies.

By the end of 2026, more countries are expected to have formalized Article 6 frameworks, published LoA criteria, and established registry interfaces. Supply is likely to grow in countries with strong institutional capacity and CA accounting infrastructure. Not all markets will move at the same speed.

The implementation of Article 6 has so far been defined by infrastructure building and constrained supply. The projection for 2026–28 is one of selective scaling, but not an immediate flood of credits.

For the market as a whole, 2026 will see continued expansion of the ICVCM’s Core Carbon Principles (CCPs). As more CCP tagged credits come to the market – including IFM, REDD+, ARR, biochar and clean cooking – CCP availability is expected to grow, as will demand.

When it comes to developing a diverse, resilient portfolio, companies that act early in securing high‑integrity supply, entering long‑term offtakes, and leveraging robust due diligence – will be best positioned to lead in 2026 and beyond.