Compliance vs Voluntary Carbon Markets

Updated 2026-11-02 · 4 min read · By the akar.earth specialist team

Compliance vs voluntary carbon markets explained: who buys, which units count, how Indonesia's PTBAE-PU and SPE-GRK fit, and where forest credits can be sold.

Compliance carbon markets exist because a law requires regulated companies to hold allowances or eligible credits; voluntary markets exist because companies choose to buy credits for climate claims or contributions. The same forest tonne can, in principle, be sold in either, but compliance schemes set strict eligibility rules, while voluntary buyers rely on standards, ratings and labels.

In Indonesia the line is now blurred by domestic rules: the national framework covers both the power-sector emissions trading system and offsets traded on IDXCarbon, and Article 6 adds a third, international layer.

Side-by-side

Indonesia’s domestic compliance layer

• PTBAE-PU: emission allowances for power generators under a cap-and-trade system, traded on IDXCarbon.
• SPE-GRK: GHG emission reduction certificates from domestic mitigation activities, tradeable on IDXCarbon and usable within domestic rules.
• IDXCarbon: the OJK-supervised exchange with four mechanisms (auction, regular, negotiated and marketplace), reporting more than 1.9 million tCO2e traded.
• Carbon tax: legislated, but implementation has been delayed; check current status.

Units traded on the exchange must be recorded in SRUK, which replaces SRN-PPI, under POJK 10/2026.

International compliance demand

• CORSIA: airlines may use eligible units from approved programmes; first-phase units need host authorisation and a corresponding adjustment.
• Sovereign Article 6 buyers: governments buying ITMOs for their NDCs. See Article 6.2 ITMOs.
• National schemes accepting international credits: for example, Singapore’s carbon tax allows companies to use eligible international credits for part of their liability, under its own criteria.
• Schemes that do not: the EU Emissions Trading System does not currently accept international offset credits.

Voluntary market quality signals

Voluntary buyers rely on:

• the ICVCM CCP label, which needs a CCP-Approved methodology under a CCP-Eligible program,
• ratings, which BeZero links to about 40% price steps between bands,
• the VCMI Claims Code for how companies describe their use of credits,
• co-benefit labels such as CCB.

Step-by-step: choosing a market for a forest project

1. Identify likely buyers and the claims they want to make.
2. Check eligibility of your activity and methodology in each target scheme.
3. Check domestic rules on registration and international transfer.
4. Decide whether to seek authorisation for some or all units. See letters of authorisation.
5. Design for the strictest target market you plan to sell into, since meeting higher requirements later is costly.
6. Keep a voluntary route open if compliance eligibility is uncertain.

How the two markets are converging

The line between compliance and voluntary carbon is narrowing in several ways:

• Shared integrity benchmarks. ICVCM’s Core Carbon Principles are used by voluntary buyers, and some compliance schemes reference similar criteria.
• Article 6 labels. Voluntary standards now tag credits that carry a letter of authorisation, so the same project can serve both markets.
• Domestic frameworks. Indonesia’s rules under Perpres 110/2025 and POJK 10/2026 bring voluntary-origin units into national registration and exchange trading.
• Disclosure rules. Corporate reporting rules increasingly require companies to say which credits they use and for what, which pushes voluntary buyers towards compliance-like evidence.

For Indonesian developers, the practical lesson is to design projects that can meet the stricter of the two sets of requirements. Data quality, legal clarity and community safeguards are valued in both. A project built only for the cheapest voluntary segment may find itself locked out when better-paying compliance or Article 6 demand appears.

Typical buyers by market

Common mistakes

• Assuming voluntary credits can be used in any compliance scheme.
• Ignoring domestic rules that apply even to voluntary exports.
• Treating “compliance-grade” as a quality label rather than an eligibility status.
• Forgetting that CORSIA eligibility depends on vintage, programme and authorisation.

See the Article 6 hub or IDXCarbon vs international registries for more. Our carbon strategy service helps you pick the right market for each part of your credit volume.