Article 6.2 vs Article 6.4: Key Differences Explained

Article 6 of the Paris Agreement establishes the framework for international carbon market cooperation, creating two distinct pathways for countries to trade emission reductions. Article 6.2 enables decentralized bilateral trading between nations, while Article 6.4 creates a centralized UN-supervised crediting mechanism. Understanding these differences is essential for carbon market participants navigating compliance strategies and credit procurement, and for anyone watching how these mechanisms will reshape the VCM.

How Article 6.2 Works: Bilateral Carbon Trading

Article 6.2 establishes a decentralized system where countries negotiate bilateral or multilateral agreements to trade ITMOs (Internationally Transferred Mitigation Outcomes). Each participating nation sets its own quality standards, designs its monitoring and verification processes, and maintains its own registry infrastructure.

This flexibility allows countries to tailor agreements to their specific needs. Switzerland, Japan, and Singapore have pioneered early bilateral deals, with the first completed ITMO transfer occurring between Switzerland and Thailand in January 2024. As of early 2025, nearly 100 bilateral agreements had been signed between approximately 60 countries, with pilot projects spanning renewable energy, cookstoves, and forestry.

The trade-off for flexibility is responsibility. Host countries must develop governance capacity to authorize credits, track transactions, and apply corresponding adjustments to their national emissions accounting. This accounting mechanism prevents double counting by adding transferred emissions back to the seller's inventory while subtracting them from the buyer's.

How Article 6.4 Works: The UN-Supervised Mechanism

Article 6.4 creates a centralized crediting system overseen by the UNFCCC's Article 6.4 Supervisory Body. Often called the Paris Agreement Crediting Mechanism (PACM), it replaces and builds upon the Kyoto Protocol's Clean Development Mechanism (CDM), which will wind down by the end of 2026.

Unlike the bilateral approach, Article 6.4 applies uniform standards across all projects. The Supervisory Body, composed of 12 rotating members, approves methodologies, registers activities, accredits verification bodies, and manages the central registry. Credits issued under this mechanism are called Article 6.4 Emission Reductions (A6.4ERs).

In February 2026, the Supervisory Body approved the first A6.4ER issuance: 60,000 credits from a clean cookstove project in Myanmar. This milestone marked the operational launch of PACM, with over 165 CDM projects now approved to transition into the new mechanism.

Article 6.4 also includes mandatory contributions: 5% of issued credits go to the Adaptation Fund (Share of Proceeds), and 2% are cancelled to support Overall Mitigation of Global Emissions (OMGE).

Article 6.2 vs Article 6.4: Key Differences at a Glance

The governance distinction is fundamental. Article 6.2 relies on country-to-country negotiations with limited central oversight, while Article 6.4 provides standardized requirements enforced by a UN body. This affects credit quality assurance: under Article 6.2, quality depends on bilateral agreement terms; under Article 6.4, the Supervisory Body sets minimum integrity thresholds.

For private sector participants, both mechanisms offer pathways to acquire credits for NDC compliance or voluntary purposes. Article 6.2 may offer faster market entry since existing voluntary market standards can be leveraged, while Article 6.4 credits may command price premiums due to their UN oversight and uniform quality guarantees.

Both mechanisms require corresponding adjustments when credits are used toward national climate targets, ensuring that emission reductions are only counted once globally.

What Article 6.4 Means for the Voluntary Carbon Market

The launch of Article 6.4 raises significant questions for the voluntary carbon market. A6.4ERs come with UN oversight, standardized methodologies, and mandatory contributions to adaptation finance, positioning them as a potential benchmark for credit integrity.

For corporate buyers, this creates new options. A6.4ERs could compete directly with VCM credits from standards like Verra and Gold Standard, or they could command a premium as a higher-integrity alternative. Some buyers may view UN-backed credits as safer from reputational risk, while others may prefer the flexibility and speed of established voluntary standards.

For project developers, Article 6.4 offers access to both compliance and voluntary buyers, but with more rigorous approval processes and mandatory levies. The question is whether the added credibility justifies the additional cost and time.

How the VCM adapts will depend on whether A6.4ERs are seen as complementary or competitive, and that will become clearer as supply grows and the market matures. Either way, the voluntary market's landscape is shifting.

Key Takeaway

Article 6.2 and Article 6.4 now operate as complementary pathways in international carbon markets. Article 6.2 offers flexibility through bilateral deals, while Article 6.4 provides centralized oversight with the first credits now issued. For voluntary market participants, Article 6.4's arrival marks a turning point: a UN-backed alternative is now live, and how it interacts with existing VCM standards will shape the market for years to come.