2.1 Capitalised terms used but not defined in this Rulebook have the meanings given in the Platform Subscription Terms and Conditions or the H2C Master Market Agreement.

2.2 References to statutes or regulatory frameworks include any amendment, replacement or successor regime.

2.3 Headings are for convenience only and do not affect interpretation.

2.4 Defined Terms

“Account” means the record maintained in the Platform for a Participant showing their holdings of PIUs, GPCs and other market entitlements.

“Additionality Index” means the Authorised Verification Agent (AVA)-approved economic threshold, expressed as a monetary value per metric tonne of qualifying low carbon fuel, representing the total revenue required by a Producer to render a production project economically viable and financeable.

The Additionality Index is calculated in accordance with H2C-published methodologies and may take into account, without limitation:
(a) the baseline market value of the relevant physical fuel molecule;
(b) the value attributable to any associated GPC1s; and
(c) the quantified emissions elimination attributable to fuel switching, as reflected through GPC3s using applicable emissions factor methodologies.

The Additionality Index is applied solely for the purposes of assessing additionality, preventing over-recovery of revenues through Environmental Attributes, and informing GPC3 price formation in accordance with this Rulebook. The Additionality Index does not constitute a representation, warranty or guarantee by H2C as to project economics, commercial returns or investment outcomes.

“Agreement” means any contractual agreement governing Environmental Attribute transactions, including the Master Market Agreement, FPAA or GPC Spot Transaction Agreement.

“Allocation Methodology” means the methodology used by a Participant to determine emissions allocations in Scope 3 reporting, such as activity-based, spend-based, tonne-km, TEU-km, or other freight allocation logic.

“Authorised Verification Agent” or “AVA” means an independent third party authorised by H2C and appointed by an Issuer to provide verification services in respect of Environmental Attributes. AVAs verify documentary evidence, provenance records and calculations, and provide assurance to Market participants that such evidence meets applicable standards.

“Baseline Molecule Value” means the value attributed to the physical baseline fuel in accordance with the Additionality Index methodology.

“Business Day” means a day (other than a Saturday, Sunday or public holiday) on which banks are open for general business in England.

“Clearing and Settlement Provider” means any third-party provider appointed by H2C to manage escrow, clearing, settlement, margin and related financial functions.

“Compliance Scheme” means any mandatory, regulatory or statutory regime in which Environmental Attributes may be claimed, recognised or reported, including but not limited to FuelEU Maritime, EU ETS or national equivalents.

“Environmental Attribute(s)” means rights associated with the reduction, avoidance or elimination of CO₂e emissions, represented by PIUs or GPCs, and excludes sulphur, nitrogen oxide or other non-CO₂e attributes unless expressly stated.

“Effective Date” means the date specified at the beginning of this Rulebook upon which this version becomes binding.

“Emission Factor” means the conversion factor used to translate fuel activity data into CO₂e emissions, consistent with recognized protocols like GHG Protocol or freight methodologies.

“Force Majeure Event” means an event beyond the reasonable control of a Party that prevents performance of obligations, as defined in the Platform Subscription Terms and Conditions.

“GPCs” means Green Premium Certificates issued under Section 9 of this Rulebook and recorded in the H2C registry.

“GPC1” means a compliance-eligible Green Premium Certificate that conveys exclusive rights to Scope 1 and Scope 2 CO₂e claims associated with a unit of low carbon fuel and which has been verified and issued in accordance with this Rulebook.

“GPC3” means a voluntary Green Premium Certificate that conveys exclusive rights to Scope 3 CO₂e claims evidenced by verified emissions elimination attributable to a fuel switching event, issued and retired in accordance with Section 9.

“GHG Protocol” means the Greenhouse Gas Protocol Corporate Standard and Technical Guidance for Scope 1, 2 and 3 emissions accounting, as may be updated from time to time.

“GLEC Framework” means the freight emissions methodology published by the Smart Freight Centre, including the GLEC Framework for Maritime Transport, aligned with GHG Protocol principles.

“H2C” means the market operator and registry operator of the H2C Global Attribute Market.

“Indicated Matching” means informal matching activity generated from PIU Requirement Listings and Pre-Verified Listings or Verified Listings that does not, by itself, create binding obligations.

“Issuers” means Producers of low carbon fuel and any intermediaries authorised to list PIUs or GPCs on the Platform.

“Legacy Baseline Fuel” means an incumbent fuel with higher carbon intensity used as a basis for calculating emissions avoided through fuel switching.

“Low Carbon Fuel” means fuel with lower lifecycle CO₂e intensity that qualifies for issuance of Environmental Attributes.

“Market” means the H2C Global Attribute Market operated under this Rulebook.

“Market Integrity Principles” means the core requirements in Section 12, including unbundling, documentary evidence, remediations and prohibited conduct.

“Material Change” means any change that could reasonably be expected to affect: (a) carbon intensity or emissions profile; (b) eligibility under any compliance or voluntary scheme; (c) the scope, timing or content of Environmental Attribute claims; or (d) the validity of supporting documentation, certification or verification, including (without limitation) any change to feedstock or feedstock supplier, production pathway, technology, energy source, certification scheme, certifier, AVA, facility boundary or capacity.

“Molecule Off‑take” means any contractual arrangement for the supply, delivery or bunkering of fuel molecules, and expressly excludes the ownership, transfer or retirement of any Environmental Attributes, PIUs or GPCs.

“Participant” means a Producer, Buyer or other entity admitted to use the Platform.

“PIUs” means Pending Issuance Units representing expected future issuance of GPCs upon verification and fulfillment of associated conditions.

“Platform” means the online technical system operated by H2C through which Participants access listings, trading mechanisms, uploading of documents, recordkeeping and retirement functions.

“Pre-Verified Listing” means a listing published by an Issuer indicating supply prior to completion of AVA verification.

“Verified Listing” means a Pre-Verified Listing that has completed AVA verification and is eligible for binding execution.

“Verification Evidence” means documentary and data evidence provided to an AVA to substantiate issuance, transfer, retirement, provenance or unbundling.

“Verified Transaction” means a transaction executed after completion of all applicable verification steps.

3.1 Role of H2C.

H2C acts solely as:
(a) market operator;
(b) registry operator; and
(c) rulebook administrator.

H2C is not a counterparty to Transactions and does not provide investment, legal, regulatory or compliance advice.

3.2 Market Oversight Committee.

(a) H2C may establish a Market Oversight Committee comprising representatives of producers, buyers, intermediaries, financiers, and independent experts.
(b) The Committee is advisory only and has no binding decision-making authority.
(c) H2C retains sole discretion in interpreting and enforcing this Rulebook.

3.3 Amendment of Rulebook.

(a) H2C may amend this Rulebook from time to time to reflect regulatory developments, market evolution, or operational requirements.
(b) Amendments shall be published on the Platform or H2C website with reasonable notice.
(c) Continued participation constitutes acceptance of the amended Rulebook.

4.1 Issuers (Producers).

Entities authorised to list and issue Environmental Attributes associated with Verified Fuel production.

4.2 Buyers (Acquirers).

Entities acquiring Environmental Attributes for compliance, voluntary, or commercial purposes.

4.3 Certification Consultants.

Organisations appointed by Issuers (Producers) to assess, advise on and support certification of methods of production, energy sources and feedstocks against recognised sustainability, production or regulatory standards. Certification Consultants may support preparation of documentation and evidence but shall not act as independent Verification Agents unless separately authorised as such under this Rulebook.

4.4 Intermediaries.

Brokers or agents authorised to facilitate Transactions on behalf of Participants.

4.5 Authorised Verification Agents (AVAs).

Independent third parties authorised by H2C and appointed by Issuers (Producers) to verify and provide assurance that all claims rights appended to PIUs and GPCs are supported by appropriate evidence, certifications and underlying data in accordance with this Rulebook and applicable standards. Authorised Verification Agents provide a trust and assurance layer for Buyers of GPCs that Environmental Attribute claims have been independently verified.

4.6 Clearing and Settlement Providers.

Third parties designated by H2C to provide clearing, escrow, margining or settlement services.

5.1 Participants must satisfy eligibility, certification, financial and compliance requirements applicable to their category.

5.2 All Participants are subject to KYC/AML, sanctions and screening procedures conducted by H2C or its designated providers.

5.3 H2C may suspend or terminate participation where eligibility requirements are no longer met.

6.1 Participants access the Market through authorised Users.

6.2 Actions taken by Users are attributed to the Participant on whose behalf they act.

6.3 Participants are responsible for internal authority controls and user access management.

7.1 The Market recognises Environmental Attributes limited to CO₂e-related greenhouse gas attributes.

7.2 Environmental Attributes are represented by: (a) Pending Issuance Units (PIUs); and (b) Green Premium Certificates (GPCs). 

7.3 The H2C registry is the authoritative system of record for Environmental Attributes.

7.4 Environmental Attributes shall not be implicitly bundled with physical fuel molecules or services.

8.1 Any designation of PIUs as verified, issuance‑eligible or compliance‑eligible is based solely on Issuer representations and AVA confirmation and does not constitute a representation or warranty by H2C

8.2PIUs represent anticipated future issuance of GPCs, subject to verification and issuance conditions.

8.3 PIUs may be listed pre-FID or post-FID and are subject to risk disclosures.

8.4 Failure to meet issuance conditions may result in lapse or cancellation of PIUs in accordance with applicable contracts.

8.5 An Issuer shall promptly notify its appointed AVA and H2C of any Material Change and shall not continue issuance, allocation, transfer or retirement of affected PIUs or GPCs unless and until AVA confirmation has been obtained

8.5 H2C may suspend issuance, allocation, transfer or retirement of affected PIUs or GPCs pending AVA confirmation following a Material Change. Such suspension is administrative only and does not constitute a technical or regulatory assessment by H2C.

9.1 Any designation of GPCs as verified, issuance‑eligible or compliance‑eligible is based solely on Issuer representations and AVA confirmation and does not constitute a representation or warranty by H2C

9.2 Categories of GPCs.

Green Premium Certificates are issued upon successful verification of Environmental Attributes and are categorised as follows:

(a) GPC1 (Compliance-Eligible Green Premium Certificate).

A GPC1 represents verified CO₂e-related Environmental Attributes issued in a standardised, unitised form to evidence the production of qualifying low carbon fuel in a manner intended to support compliance with applicable regulatory or mandatory schemes, including where relevant FuelEU Maritime, the EU Emissions Trading System (EU ETS), the Corporate Sustainability Reporting Directive (CSRD) and related national implementing measures. A GPC1 is registered in the H2C registry and is issued and transferred by an Issuer (Producer) concurrently with the shipment of one metric tonne (or such other unit as specified by H2C) of qualifying low carbon fuel. GPC1s are transacted only alongside the corresponding physical product and confer a guarantee of origin and exclusive, unitised rights to verified Scope 1 and Scope 2 CO₂e-related claims arising from the production of that product. A GPC1 may be issued only where the underlying production pathways, methodologies, energy sources, feedstocks, data and verification evidence satisfy the applicable regulatory eligibility criteria in force at the time of issuance, as confirmed by an Authorised Verification Agent. Eligibility of a GPC1 for any specific compliance obligation is determined solely by the relevant regulator or competent authority, and neither registration nor issuance of a GPC1 constitutes a representation, warranty or guarantee of regulatory acceptance.

(b) GPC3 (Voluntary Green Premium Certificate).

A GPC3 is a linked certificate issued in connection with, and following the retirement of, a corresponding GPC1. GPC3s represent verified CO₂e-related Environmental Attributes associated with Scope 3 emissions and provide unitised claims rights to the elimination of one metric tonne of CO₂e from indirect emissions embedded in products and services within low carbon fuel-powered supply chains. GPC3s represent a metric tonne of CO₂e eliminated from Scope 3 emissions and are issued solely for voluntary, commercial or non-mandated purposes, including deductions from voluntary emissions accounting, internal decarbonisation targets, supply chain reporting and contractual claims. The number of GPC3s issued in respect of each GPC1 retired shall be calculated in accordance with the SBTi emissions factor methodology (or such successor methodology as may be recognised by H2C from time to time).

(c) Claims Integrity.

Both GPC1s and GPC3s confer exclusive rights only to the verified Environmental Attributes recorded in the H2C registry. The classification of a GPC as GPC1 or GPC3 determines the intended use context of the certificate but does not alter the requirement that all associated CO₂e claims be supported by appropriate evidence, verification and registry records in accordance with this Rulebook. 

9.3 GPCs are uniquely identifiable, traceable and recorded in the registry.

9.4 Contractual Unbundling.

GPCs may be held, transferred and retired only in accordance with this Rulebook. GPCs constitute Environmental Attributes that are contractually and legally unbundled from the sale, purchase, delivery or provision of any low carbon fuel, energy, transport or related services. Except as expressly permitted under this Rulebook, no transfer of physical fuel molecules or services shall convey, imply or include any rights to Environmental Attributes or associated CO₂e claims unless such rights are expressly evidenced by the corresponding GPCs recorded in the H2C registry.

9.5 Additionality Index and GPC3 Price Formation.

In order to support robust additionality and to ensure that GPC3s reflect genuine financing of emissions elimination through fuel switching, H2C shall apply an Authorised Verification Agent (AVA)-approved additionality index to eligible production projects. The additionality index represents the total revenue per metric tonne of low carbon fuel required by the Producer to render the relevant project economically viable and financeable.

(a) The additionality index shall be expressed as a monetary value per metric tonne of fuel and may be calculated by reference to the following indicative formulation:

Additionality Index = Baseline molecule value + GPC1 value + [Applicable emissions factor × GPC3 value]

(b) The baseline molecule value, GPC1 value, applicable emissions factor assumptions and any resulting GPC3 value shall be disclosed, documented and subject to verification or review by an AVA in accordance with H2C-published methodologies.

(c) Where the AVA-approved additionality index for a project is equal to or less than the combined value of the baseline molecule and the associated GPC1, the asking price for any corresponding GPC3s shall be deemed to be zero, reflecting that no additional Scope 3 financing contribution is required to achieve project viability.

(d) The application of an additionality index does not constitute a representation or guarantee by H2C as to project economics, profitability or investment outcomes, but serves solely as a market integrity mechanism to support credible additionality and to prevent over-recovery of revenues through Environmental Attributes.

9.6 An Issuer shall promptly notify its appointed AVA and H2C of any Material Change and shall not continue issuance, allocation, transfer or retirement of affected PIUs or GPCs unless and until AVA confirmation has been obtained

9.7 H2C may suspend issuance, allocation, transfer or retirement of affected PIUs or GPCs pending AVA confirmation following a Material Change. Such suspension is administrative only and does not constitute a technical or regulatory assessment by H2C.

10.1 Pre-Verified Listings.

Indicative listings published for supply signalling only.

10.2 PIU Requirement Listings.

Indicative demand-side listings.

10.3 Verified Listings (AVA-Verified).

Listings that have been verified by an Authorised Verification Agent (AVA) and are intended to result in Transactions.

10.4 Listings must include required disclosures specified by H2C, which shall typically include, without limitation, proof of provenance documentation, production records, shipment and delivery documentation, and such other evidence as may be required to support verification by an Authorised Verification Agent (AVA).

10.5 Verified Listing Commitment Period (VLCP).

Where PIUs have completed AVA verification and are issued and listed to attract bids, the Issuer shall be subject to a Verified Listing Commitment Period during which it may not withdraw, materially amend or bypass the listing, or contract the same Environmental Attributes outside the Platform, except for Permitted Withdrawal Events.

11.1 The Market supports spot trading, forward trading (including transactions entered into pursuant to Forward PIU Allocation Agreements (FPAAs)) and auction-based mechanisms. FPAAs are bilateral forward contracts governing the future allocation, issuance and delivery of PIUs and/or GPCs, the detailed terms of which are set out in the applicable FPAA and the H2C Master Market Agreement.

11.2 Two-Stage Matching Process.

The Market operates a two-stage matching process for forward and pre-issuance activity:

(a) Indicative Matching and Demand Signalling. PIU Requirement Listings may be matched on an indicative, non-binding basis with Pre-Verified Listings or Verified Listings. In each case, an Acquirer may note interest through the Platform, which constitutes an informal demand signal only and does not create any obligation to transact.

(b) Verified Execution Stage. No binding Transaction may be executed unless and until all applicable verification steps have been completed and the relevant Listing qualifies as a Verified Listing (AVA-Verified). Once verification is complete, H2C may, at the request of the relevant Participants, facilitate or organise a sales process, auction or execution workflow in accordance with Platform procedures and applicable contractual documentation.

11.3 Commercial Terms, Synchronisation and Standard Agreements.

(a) Post‑Award Conversion Window. Immediately upon Bid Acceptance, and as a condition to securing the award, Buyer and Seller shall execute a Forward PIU Allocation Agreement (FPAA). Execution of the FPAA confirms the award, conditionally allocates the relevant Verified PIUs, and creates binding economic off‑take of Environmental Attributes. Any agreement governing (b) Molecule Off‑take (the Molecule Off‑take Agreement) is legally separate from the FPAA and must be concluded within the applicable Post‑Award Conversion Window. During this window, PIU price, volume and delivery window are locked and only operational or logistical terms of Molecule Off‑take may be finalised. Any Molecule Off‑take Agreement must include contractual unbundling provisions consistent with this Rulebook.

11.4 No Obligation to Transact.

Indicative matching, expressions of interest or demand signals do not oblige any Participant to enter into a Transaction, nor do they constitute an offer, acceptance or commitment until documented under the applicable H2C standard market agreements.

11.5 The VLCP applies prior to any Bid Acceptance and does not oblige an Issuer to accept any bid or conclude a transaction.

12.1 Market Integrity and Attribute Unbundling.

(a) Strict adherence to the contractual and legal unbundling of Environmental Attributes from physical fuel, energy, transport and related services is fundamental to the integrity of the Market.

(b) Any failure to properly unbundle Environmental Attributes, any implicit or misleading conveyance of CO₂e claims outside the H2C registry, or any attempt to create, transfer or assert Environmental Attribute claims otherwise than through the issuance, transfer and retirement of GPCs in accordance with this Rulebook shall constitute a serious breach of these market rules.

(c) All sales, purchases and resales of low carbon fuel entered into by Participants must include contractual provisions that expressly exclude Environmental Attributes and associated CO₂e claims (including Scope 1, Scope 2 and Scope 3 claims), except to the extent such claims are expressly conveyed through corresponding GPCs recorded in the H2C registry.

(d) Such contractual provisions shall be consistent with H2C-approved environmental attribute unbundling clauses or carve-outs, as may be specified from time to time.

(e) Evidence of compliance with the unbundling requirements in this Section 12.1, including executed contractual carve-outs and related provisions, must be uploaded to and maintained within the H2C Platform document repository in accordance with Platform procedures. Such documentation may be referenced by GPCs in the H2C registry as supporting evidence of valid contractual separation.

(f) Fuel users and downstream purchasers shall not make fuel-switch, substitution or emissions elimination claims for the purposes of their clients’ or counterparties’ Scope 3 emissions accounting unless such claims are supported by the contractual separation, purchase and transfer of the corresponding GPC3s recorded in the H2C registry.

(g) Remedial Payment. Without prejudice to any other rights or remedies, where a Participant breaches this Section 12.1 by failing to properly unbundle Environmental Attributes or by making unauthorised CO₂e claims, H2C may require such Participant to procure and transfer to the relevant GPC holder(s), or retire on their behalf, the corresponding GPCs at the prevailing asking price published on the Platform (or, where no current asking price exists, a price determined in accordance with H2C‑published methodologies), together with any reasonable costs incurred in connection with such remediation.

12.2 Prohibited Conduct. Participants shall not engage in conduct that is misleading, manipulative, abusive or disorderly. Without limitation, prohibited conduct includes:
(a) false, inaccurate or misleading listings, disclosures or statements;
(b) artificial, deceptive or misleading supply or demand signalling;
(c) wash, circular or non‑bona fide transactions;
(d) collusion, coordination or other conduct intended to distort market outcomes;
(e) circumvention of Platform processes, controls or safeguards, including any failure to comply with the unbundling requirements set out in Section 12.1.

12.3 Market Abuse Standard. Conduct that would reasonably be considered market abuse, manipulation or disorderly trading in comparable regulated markets may constitute a breach of this Rulebook, whether or not such conduct is expressly listed above.

12.4 Further Provisions.

This Section 12 may be augmented from time to time to include additional provisions relating to market surveillance, investigation and evidence‑gathering powers, graduated enforcement measures (including suspension, cancellation, forced retirement and exclusion), and appeals or review processes, in each case in accordance with amendments to this Rulebook.Item description

13.1 Clearing and settlement are conducted exclusively by designated third-party providers appointed by H2C, which may include clearinghouses, escrow agents, payment service providers and other financial intermediaries. Such third-party providers may also perform, or support the performance of, know-your-customer (KYC), anti-money laundering (AML), sanctions screening and related compliance checks in accordance with applicable laws, regulations and H2C policies. Participants acknowledge and agree that access to, and continued use of, the Market may be conditional upon the successful completion and ongoing satisfaction of such third-party checks.

13.2 H2C does not hold or control Participant funds and shall receive applicable GPC issuance fees, transaction fees and other Platform charges directly from the relevant clearing and settlement provider in accordance with H2C’s published fee schedules and arrangements with such providers.

14.1 Request for Retirement.

A holder of GPCs may request retirement of such GPCs through the Platform in accordance with H2C-published procedures. Retirement requests must specify, where applicable, the purpose of retirement (including compliance, voluntary reporting, contractual claims or Scope 3 accounting) and any required attribution details.

14.2 Preconditions to Retirement.

Retirement of GPCs may be subject to verification that:
(a) the requesting party is the lawful holder of the relevant GPCs;
(b) any required verification, transfer or settlement steps have been completed;
(c) for GPC3s, the corresponding GPC1 has been validly retired in accordance with this Rulebook; and
(d) all applicable fees have been paid.

14.3 Irrevocability.

Retirement of GPCs is final and irreversible. Retired GPCs may not be transferred, reused or reissued under any circumstances.

14.4 Registry Record and Evidence.

Upon retirement, the H2C registry shall record the retirement event, including the identity of the retiring party, the date of retirement, the category of GPC retired and any associated claim references. Registry retirement records constitute conclusive evidence, for the purposes of the Market, of the retirement and the associated Environmental Attribute claims.

14.5 Claims Use and Limitations.

Environmental Attribute claims arising from retired GPCs may be made only in accordance with:
(a) the category of GPC retired (GPC1 or GPC3);
(b) the scope of claims expressly conferred by such GPCs as set out in this Rulebook; and
(c) applicable regulatory, accounting or reporting frameworks.

14.6 Use-Based Condition for GPC1 Claims.

Claims associated with retired GPC1s may be made only once the corresponding low carbon fuel to which such GPC1s relate has been physically delivered and consumed or otherwise used for its intended purpose. Retirement of a GPC1 prior to such use does not, of itself, entitle the holder to make Scope 1 or Scope 2 emissions claims until such use has occurred.

14.7 Causality and Accounting Framework Alignment for GPC3 Claims.

Claims associated with retired GPC3s may be made only where the claimant can demonstrate a reasonable, auditable and documented causal link between:
(a) the combustion or use of the relevant low carbon fuel;
(b) the claimant’s products, services or value-chain activities giving rise to Scope 3 emissions; and
(c) the elimination of one metric tonne of CO₂e evidenced by the corresponding GPC3.

Such causality must be established and documented in a manner consistent with recognised global accounting and reporting frameworks, including the Greenhouse Gas Protocol (in particular the Corporate Value Chain (Scope 3) Standard and associated technical guidance), the Science Based Targets initiative (SBTi) guidance on transport, logistics and value-chain decarbonisation, and freight-specific calculation methodologies such as the Smart Freight Centre Global Logistics Emissions Council (GLEC) Framework or Clean Cargo methodologies, as applicable. H2C does not prescribe the specific allocation methodology to be used by claimants; rather, claimants are responsible for applying their chosen methodology consistently, transparently and in a manner that can be substantiated by evidence.

GPC3s evidence the financing of a verified real-world fuel switching event resulting in emissions elimination and do not constitute offsets, allowances or compliance instruments. Claims may be made only upon retirement of the relevant GPC3s and must reference the applicable reporting boundary, time period and claim purpose recorded in the H2C registry.

14.8 No Over-Claiming.

No claim may be made that exceeds, contradicts or is inconsistent with the rights evidenced by the retired GPCs recorded in the H2C registry.

14.9 No Guarantee of Regulatory Acceptance.

Retirement of GPCs and the recording of associated claims in the H2C registry do not constitute a representation, warranty or guarantee by H2C that such claims will be accepted by any regulator, authority, auditor or third party.

15.1 Authorised Verification Agents (AVAs).

For the purposes of this Rulebook, an Authorised Verification Agent (AVA) is a competent, independent organisation authorised by H2C to provide verification and assurance services in respect of Environmental Attributes. AVAs assess whether claims of provenance, issuance, transfer and retirement of PIUs and GPCs are supported by credible, complete and trustworthy evidence in accordance with this Rulebook and applicable standards. AVAs do not certify methods of production, energy sources or feedstocks; rather, they provide Buyers and other Market participants with an independent trust layer that claims of provenance and associated Environmental Attribute rights can be appropriately substantiated.

15.2 Verification Scope and Evidence.

Verification must be conducted by Authorised Verification Agents (AVAs) under recognised standards and in accordance with this Rulebook. Verification shall be based on a review of relevant evidence and documentation, which may include, without limitation: proof of provenance records; certification documents; production methodologies; energy source and feedstock data; lifecycle emissions calculations; shipment, delivery and use records; contractual unbundling provisions; and any other data or documents reasonably required to substantiate the issuance, transfer or retirement of PIUs or GPCs and the associated Environmental Attribute claims.

15.3 Verification of GPC3 Quantification and Claims Evidence.

 Without limiting Section 15.1, where verification relates to the issuance, transfer or retirement of GPC3s, Authorised Verification Agents shall, acting in accordance with their professional standards, assess whether the emissions elimination calculations, baseline assumptions and supporting evidence are consistent with recognised global accounting and reporting frameworks, including the Greenhouse Gas Protocol, Science Based Targets initiative (SBTi) guidance and applicable freight or shipping methodologies (such as the Smart Freight Centre GLEC Framework or Clean Cargo methodologies). Verification shall include a review of the provenance, completeness and internal consistency of the documentation relied upon, but shall not require AVAs to opine on the appropriateness of a Participant’s chosen Scope 3 accounting methodology as a matter of policy or regulatory interpretation.

15.4 Reliance and Responsibility.

H2C does not guarantee verification outcomes, and responsibility for the selection of accounting frameworks, allocation methodologies and claims made using retired GPC3s remains solely with the relevant Participant.

16.1 Regulatory Alignment and Exclusivity of GPC1s.

GPC1s carry Environmental Attribute rights from the point of production of the qualifying low carbon fuel through to its combustion or use and are designed to be retired synchronously with the submission of claims under applicable mandatory or regulatory schemes, including FuelEU Maritime, the EU Emissions Trading System (EU ETS) and the Corporate Sustainability Reporting Directive (CSRD). GPC1s are not affected by, nor do they modify, the substantive eligibility criteria, thresholds or conditions of such schemes; however, a validly issued and retired GPC1 entitles its holder to submit the corresponding verified Scope 1 and Scope 2 CO₂e claims as part of its compliance submissions, subject always to acceptance by the relevant regulator or competent authority. As the contractual and legal flipside of unbundling, each GPC1 provides the holder with exclusive, unitised and segregated contractual rights to the Environmental Attributes and associated Scope 1 and Scope 2 CO₂e claims recorded in the H2C registry, to the exclusion of all other parties.

16.2 Participants remain solely responsible for regulatory compliance, including the preparation, submission and management of any compliance filings, reports or disclosures to regulators or competent authorities, which are not managed, administered or governed by H2C or the Market.

16.3 Scope 3 Framework Interaction and Exclusivity of GPC3s.

GPC3s are designed to operate as in-sector emissions elimination instruments within established Scope 3 accounting frameworks. Participants using GPC3s for reporting or disclosure purposes should apply a layered approach whereby: (a) gross Scope 3 emissions are calculated in accordance with the applicable methodology (including activity-based or factor-based methods under the Greenhouse Gas Protocol and freight methodologies such as GLEC or Clean Cargo); and (b) the impact of retired GPC3s is disclosed separately as a value-chain intervention representing verified emissions elimination enabled by fuel switching. As the contractual and legal flipside of unbundling, each retired GPC3 confers exclusive, unitised and segregated contractual rights to the Scope 3 CO₂e claims evidenced by that certificate, and such claims may be asserted only by the holder identified in the H2C registry at the time of retirement. GPC3s must not be used to substitute or restate another entity’s Scope 1 emissions inventory or to make claims beyond the scope of the rights evidenced by the retired certificates.

17.1 Failure Events.

Failure events include, without limitation:
(a) non-issuance of GPCs or conversion of PIUs into GPCs in accordance with agreed timelines or verification conditions;
(b) non-delivery or late delivery of low carbon fuel where delivery is a condition precedent to issuance, transfer or retirement of GPCs;
(c) delivery of fuel, Environmental Attributes or services materially outside the contracted specifications, volumes, timing windows or quality parameters;
(d) failure to deliver, substantiate or maintain the contracted provenance, certification or verification benefits associated with PIUs or GPCs;
(e) invalidation, suspension or withdrawal of verification, certification or eligibility status by an Authorised Verification Agent or competent authority;
(f) non-payment, late payment or failure to satisfy escrow, margin or deposit requirements under applicable agreements.

17.2 Consequences and Contractual Remedies.

The consequences of any Failure Event, including termination rights, make-good obligations, replacement sourcing, price adjustments, damages, liquidated damages, escrow drawdowns or other remedies, shall be governed by the applicable contractual documentation, including the H2C Master Market Agreement, any FPAA, GPC Spot Transaction Agreement or related Transaction documents. Nothing in this Rulebook limits the availability of contractual or legal remedies as between transacting parties.

17.3 Reserves and Risk Adjustments.

Where appropriate, and in accordance with H2C-published methodologies and AVA recommendations, a portion of PIUs or prospective GPC issuance may be designated as a reserve or holdback at the point of issuance or conversion, to reflect risks of non-delivery, late delivery or verification uncertainty. Such reserves may be released, adjusted or cancelled based on subsequent verification outcomes, delivery performance or other relevant risk factors, as documented in the registry and applicable Transaction agreements.

18.1 Investigations and Information Requests.

H2C may, acting reasonably, investigate any suspected or alleged breach of this Rulebook, applicable Platform terms or Market integrity principles. For such purposes, H2C may request information, documents or explanations from Participants, AVAs or Clearing and Settlement Providers, subject to applicable law.

18.2 Interim Measures.

Where H2C reasonably considers that immediate action is required to protect Market integrity, Participants or the registry, H2C may impose interim measures, including temporary suspension of listings, trading privileges, issuance, transfer or retirement of Environmental Attributes, pending completion of an investigation.

18.3 Sanctions.

Where H2C determines that a Participant has breached this Rulebook, H2C may impose one or more of the following sanctions, proportionate to the nature, seriousness and impact of the breach:
(a) issuance of warnings or directions for corrective action;
(b) mandatory remediation, including measures set out in Section 12.1(f);
(c) cancellation or correction of listings;
(d) suspension or restriction of Market access or specific activities;
(e) suspension or revocation of eligibility to issue, acquire or transfer PIUs or GPCs;
(f) permanent exclusion from the Market in cases of serious or repeated breaches.

18.4 No Limitation of Contractual Remedies.

Sanctions imposed under this Rulebook are without prejudice to any rights, remedies or claims available to H2C or other Participants under applicable contracts, including the Platform Subscription Terms and Conditions, the H2C Master Market Agreement, any FPAA or Transaction documentation.

18.5 No Duty of Care.

Nothing in this Rulebook creates any duty of care, fiduciary obligation or liability on the part of H2C towards any Participant in respect of monitoring, surveillance, enforcement or any failure to enforce any provision of this Rulebook.

18.6 Discretion and No Obligation to Enforce.

H2C retains discretion as to whether, when and how to exercise its enforcement powers under this Rulebook and is not obliged to pursue enforcement action in every case of a suspected or actual breach.

18.7 Appeals.

H2C may, but is not obliged to, establish procedures for Participants to request review of enforcement decisions. Any such procedures shall be advisory only and shall not limit H2C’s discretion or authority under this Rulebook.

19.1 Authoritative Records.

The H2C Platform, including the registry and associated systems, constitutes the authoritative system of record for Environmental Attributes traded, held, transferred and retired within the Market. Registry records relating to the issuance, holding, transfer and retirement of PIUs and GPCs shall be conclusive evidence, for the purposes of the Market, of the status and ownership of such Environmental Attributes.

19.2 Documentary Evidence and Provenance Records.

The Platform includes functionality for the upload, storage and management of documentary evidence supporting provenance, verification and compliance, including production records, certification documents, verification statements, contractual unbundling clauses, delivery and use records and other supporting documentation. Such documents form part of the evidentiary chain supporting PIUs and GPCs and may be referenced directly from registry entries.

19.3 Audit Trails and Agreement Records.

The Platform maintains audit trails in respect of:
(a) creation, amendment and acceptance of Platform Subscription Terms and Conditions, the Rulebook and other applicable agreements;
(b) execution and lifecycle events relating to Transactions, FPAAs and other market agreements to the extent processed through the Platform;
(c) user actions, permissions and role-based access;
(d) listings, matching activity, issuance, transfer and retirement of PIUs and GPCs.

19.4 Certificate Registry Records.

All registrations, transfers and retirements of GPCs are time-stamped, uniquely identifiable and recorded in the H2C registry, together with the identity of the relevant holder, transferee or retiring party and any associated claim references. Such records provide a permanent, immutable audit trail for Environmental Attribute claims made within the Market.

19.5 Evidentiary Status and Retention.

Records maintained by the Platform under this Section 19 may be relied upon by Participants, AVAs and auditors as evidence of market activity and claims provenance, subject to applicable law. H2C shall retain such records for such minimum periods as may be required by applicable law, regulation or H2C-published data retention policies.

19.6 Limitations.

While H2C maintains robust systems for recordkeeping and audit trails, H2C does not guarantee the accuracy or completeness of data uploaded by Participants and shall not be responsible for errors, omissions or misstatements in Participant-provided information. Processing of any Personal Data in connection with records and audit trails under this Rulebook is governed exclusively by the Data Processing Addendum incorporated into the Platform Subscription Terms and Conditions.

20.1 Systems Availability and Suspension.

H2C operates the Platform using reasonable skill and care but does not guarantee uninterrupted or error-free operation. H2C may suspend, restrict or limit access to all or part of the Market where reasonably necessary for system maintenance, upgrades, security incidents, capacity constraints, emergency situations or to protect Market integrity. H2C shall use reasonable endeavours to minimise disruption and, where practicable, provide advance notice of planned suspensions.

20.2 Force Majeure (Rulebook Context).

The operation of the Market and performance of H2C’s obligations under this Rulebook may be affected by events beyond H2C’s reasonable control. Force majeure concepts applicable to Participants and H2C are governed primarily by the Platform Subscription Terms and Conditions, which all Participants are required to accept as a condition of Market access.

20.3 No Market Liability for Force Majeure Impacts.

Without prejudice to the Platform Subscription Terms and Conditions, H2C shall not be liable under this Rulebook for any failure, delay or suspension of the Market arising from a Force Majeure Event, including events affecting third-party infrastructure, clearing and settlement providers, verification services, data providers or communications networks.

20.4 Interaction with Transactions.

The occurrence of a Force Majeure Event does not, of itself, excuse performance of obligations under Transactions, FPAAs or other bilateral agreements, which shall be governed by the force majeure and hardship provisions of the applicable contracts between Buyers and Sellers.

20.5 Market Integrity Measures.

During a Force Majeure Event, H2C may take such reasonable measures as it considers necessary to maintain orderly Market operation, including suspension of listings, issuance, transfers or retirements, or the imposition of temporary conditions or controls, without liability

21.1 Market Data for Guidance Only.

Any market data, analytics, pricing indicators, indices, benchmarks, reference prices or other information published or made available by H2C through the Platform (whether aggregated, anonymised or otherwise) are provided for general informational and guidance purposes only. Such information does not constitute, and shall not be construed as, a recommendation, valuation, offer, solicitation or advice, nor does it establish, influence or determine prices, volumes or commercial terms of Transactions, which are agreed solely between Buyers and Sellers.

21.2 No Price Setting or Market Making.

H2C does not act as a price-setting body, market maker or principal and does not guarantee the accuracy, completeness or suitability of any market data for any particular purpose. Participants remain solely responsible for their own pricing decisions, commercial negotiations and risk assessments.

21.3 Confidentiality of Participant Information.

Non-public information relating to Participants, Transactions, listings, positions or documentation shall be treated as confidential by H2C, subject to disclosure as required by law, regulation, court order, regulatory request, or as necessary for the operation of the Market, including to AVAs, clearing and settlement providers or professional advisers acting under confidentiality obligations.

21.4 Transparency Reporting.

H2C may publish periodic transparency reports, market summaries or aggregated statistics relating to Market activity, volumes, issuance, transfers, retirements and environmental impact, provided that such publications do not disclose confidential Participant information.

22.1 Version Control.

This Rulebook is identified by version number and effective date. Each version supersedes all prior versions from its effective date.

22.2 Updates and Amendments.

H2C may update or amend this Rulebook from time to time to reflect regulatory developments, market evolution, operational requirements or risk management considerations. Updated versions shall be published on the Platform or H2C website.

22.3 Notice of Changes.

H2C shall use reasonable endeavours to provide advance notice of material changes to this Rulebook, including by Platform notification or electronic communication. Non-material or technical changes may take effect without prior notice.

22.4 Acceptance of Updated Rulebook.

Continued access to or use of the Platform or participation in the Market following the effective date of an updated Rulebook constitutes acceptance of the updated Rulebook.

22.5 Effective Date.

This Rulebook is effective as of the Effective Date specified on the cover page.

24.1 This Rulebook is governed by English law.

Copyright 2026 H2C t/a First Carbon Investments Group Ltd. For a hard copy please contact info@h2c.org