Moving Carbon Credits Between EcoRegistry and Carbonmark: A Technical Guide

A practical guide for project developers, traders, and buyers holding EcoRegistry credits.

EcoRegistry-issued carbon credits can be transferred into a Carbonmark account on the Base network, listed for sale or retired there, and sent back to EcoRegistry. This guide covers what EcoRegistry is, how to move credits in each direction, how retirements are recorded on both platforms, where listed credits are available on Carbonmark, and how both organizations are aligning their data on the Carbon Data Open Protocol (CDOP).

Key Takeaways

• EcoRegistry credits can be transferred into a Carbonmark account and listed for sale, and moved back to EcoRegistry when needed. The transfer is initiated inside EcoRegistry via their Base Blockchain transfer tool.
• Returns must come from the same account. Credits can only be exported back to EcoRegistry from the Carbonmark account, and Base wallet address, that originally received them.
• Retirements are recorded on both sides. A retirement through Carbonmark is recorded onchain with a public Carbonmark certificate, and a matching retirement is recorded on EcoRegistry on a 1:1 basis.
• Whole tonnes only, for now. EcoRegistry-issued credits retire in whole tonnes on Carbonmark; fractional retirement is in progress.
• CDOP is an open-source data schema for carbon credits, co-chaired by GCMU, Sylvera, RMI, and S&P Global Commodity Insights. Version 2.0 shipped in September 2026 with 11 data categories. EcoRegistry already implements Version 1.0 and is moving toward 2.0; Carbonmark is aligning its own project and credit data with the same schema.

What EcoRegistry is

EcoRegistry is a registry platform for carbon credits based in Medellín, Colombia. It describes itself as the first blockchain-based carbon credit registry, and it grew into Latin America's most prominent registry as Colombia's carbon tax began accepting credits as an offset against tax liability.

Its best-known role is as the registry provider for Cercarbono, the Colombian-born certification standard. The two are independent companies that have worked together since 2018. Cercarbono certifies the project and issues the credits; EcoRegistry records issuance, tracks every transfer, and records retirements so a unit cannot be claimed twice. Cercarbono is endorsed by the International Carbon Reduction and Offset Alliance (ICROA) and reports more than 200 registered projects across 20+ countries. It has been named Environmental Finance's "Best GHG Crediting Programme / Standards Setter" for two consecutive years.

The types of projects EcoRegistry supports

EcoRegistry's project base reflects where it was developed. Forestry dominates, especially REDD+ (avoided deforestation) projects led by Afro-descendant and Indigenous communities on the Pacific coast and in the Amazon basin. Around that core sit afforestation and reforestation, agriculture and land-use projects, renewable energy, and methane abatement. Cercarbono's methodology catalogue also extends beyond carbon into biodiversity and circular-economy credits, though those are not yet part of the Carbonmark connection.

Two of those projects were the first EcoRegistry listings on Carbonmark when the partnership was announced in September 2024: Proyecto Conservación ARLEQUÍN REDD+ (ECO-22), protecting 82,626 hectares of rainforest in the Chocó biogeographic region, and Proyecto REDD+ PAZcífico Sur (ECO-114), covering 371,749 hectares in Nariño with 18 Afro-descendant communities who own the land.

The technology EcoRegistry uses

EcoRegistry's differentiator among registries is that it treats the credit ledger as shared infrastructure rather than a private database. Four decisions illustrate that.

• Distributed ledger from the start. EcoRegistry records units on a distributed ledger after issuance, so the chain of custody from issuance through transfer to retirement is traceable and publicly checkable. This is the property that makes a clean handshake with an onchain marketplace like Carbonmark possible in the first place.
• Exchange and registry connectivity. EcoRegistry's suite of APIs allow third party platforms to sync carbon credit processes and events with their registry, ensuring credit integrity, while also allowing builders to create new conduits for climate finance and novel products/services leveraging their credits.
• Financial-grade identifiers. In February 2026 EcoRegistry became the first registry to integrate CUSIP Global Services' request mechanism for the voluntary carbon market, so every project on the platform can be linked to a CUSIP identifier of the kind used for securities. That gives banks, auditors, and data providers a familiar key to match credits across systems.
• Registry-layer tokenization. In July 2025 EcoRegistry and the International Carbon Registry (ICR) completed testing on Kinexys by J.P. Morgan's blockchain application for tokenizing credits at the registry level, so a credit can be represented as a token at its source and settle between buyer and seller without leaving the registry's control.

On the data side, EcoRegistry was one of the 37 signatories when CDOP Version 1.0 launched in September 2025, and it already structures its project data to that schema. We've provided more on why that matters below.

How to transfer credits from EcoRegistry to Carbonmark

This is the path for a project developer or trader who holds credits on EcoRegistry and wants to list them for sale, or retire them, through Carbonmark.

Before you start

• An active Carbonmark account, verified through onboarding, with a Base network wallet established after onboarding (this can be done in a self-service manner via Carbonmark's account tooling).
• An active EcoRegistry account holding the credits you want to move.

Each transfer

1. When logged in to your EcoRegistry account, navigate to the trading menu and select Base Network.
2. Select the project, vintage, and batch amount you'd like to send to your Carbonmark account. Update the Wallet field with the Base wallet address assigned to your Carbonmark account.
3. Double check your Base wallet address on both platforms to ensure credits are transferred correctly.
4. Click Transfer. Your credits will arrive to your Carbonmark account in a few seconds and be viewable from your Carbon Portfolio page.

Then list or retire. Once credits appear in your Portfolio, set your price and list them on the Marketplace, or retire them in your own name. Carbonmark charges sellers nothing to onboard or list; fees apply on the buyer side when a transaction happens.

Whole tonnes only, for now. As of August 2026, EcoRegistry-issued credits can be retired on Carbonmark only in whole-tonne units, not the 1 kg fractions available on other credit types. We are working with EcoRegistry to support fractional retirement.

The full procedure, with screenshots, is in the EcoRegistry import guide in our developer docs, alongside an overview of how Carbonmark integrates registries.

How to transfer credits from Carbonmark to EcoRegistry

The return path matters just as much. A buyer who wants to hold credits in their own EcoRegistry account, or a seller who wants to withdraw unsold inventory, should be able to leave without friction.

Before you start

• Logged in to both Carbonmark and EcoRegistry.
• EcoRegistry-issued credits in your Carbonmark Portfolio.
• The same Carbonmark account that received the credits. Exports must be sent from the Carbonmark account (and its Base wallet address) that originally received the credits from EcoRegistry. Credits cannot be returned to EcoRegistry from a different Carbonmark account.

Each transfer

1. From the Carbonmark account that received the credits, navigate to the Carbon Portfolio menu.
2. Select Export Carbon Credits and then select EcoRegistry.
3. Select your project and the number of credits you'd like to transfer back to your EcoRegistry account.
4. Review the details and confirm that the sending wallet address is the same Base address you entered in EcoRegistry during the original transfer, then select Transfer.
5. Log in to EcoRegistry and check that the project and quantity appear in your inventory.

Both directions are documented step by step in the transfer credits guide in our developer docs.

How retirements are recorded

When an EcoRegistry credit is retired through Carbonmark, the retirement is recorded onchain with a public Carbonmark certificate, and a matching retirement is recorded on EcoRegistry on a 1:1 basis, so the registry certificate and the onchain certificate describe the same tonne. Each unique retirement event page on Carbonmark includes the onchain transaction information, Carbonmark PDF certificate, and link to the certificate issued on the registry side.

• Public proof of every retirement. Each retirement produces an onchain transaction hash and a certificate at app.carbonmark.com/retirements/{address}/{number} that anyone can open. Buyers use this in sustainability reports; sellers use it as evidence that their credits were retired, not resold.
• Fractional retirement. On credit types where the registry supports it, Carbonmark retires from 0.001 tCO₂e (1 kg). This is what makes per-transaction, per-product, and per-inference offsetting possible. EcoRegistry credits currently retire in whole tonnes (see above).

Where listed credits are available

A single listing is visible to every Carbonmark channel at the same time: the Marketplace, the API, hosted checkout links, and the agent endpoints. Sellers do not maintain separate inventory per channel.

• Marketplace (app.carbonmark.com). Self-serve buying and retiring for businesses and individuals, with card payment via Stripe. Buyers filter by project type, country, registry, vintage, co-benefits, and price.
• Carbonmark API. Programmatic discovery, quoting, and retirement for software companies, fintechs, logistics platforms, and ESG reporting tools. Version 20 is the current stable release. Integrators retire on demand with no pre-purchased inventory, which means a seller's listing can be consumed one tonne at a time by dozens of applications. The developer docs cover the full flow.
• API Checkout Service. Hosted, Stripe-powered checkout links so an e-commerce store or app can sell and retire credits without building payment infrastructure. See API and Integrations for an overview of both.
• Agent endpoints (x402 and MCP). Carbonmark's x402 endpoint on the Base blockchain lets AI agents discover credits, quote live prices, pay in USDC, and retire in a single HTTP flow. A Model Context Protocol (MCP) integration exposes the same actions to agent frameworks.

Why list on Carbonmark

• Zero-cost onboarding, no exclusivity. There are no seller-side listing fees and no requirement to delist elsewhere. Sellers set their own price and can change it at any time.
• Instant settlement. Payment arrives when the credit sells. Sellers can settle in stablecoins onchain or offramp to a bank account through Carbonmark's bank-payout partner.
• A track record. Carbonmark has retired more than 1,200,000 tCO₂e on behalf of clients across 150+ listed projects on six continents.

How Carbonmark records and connects

• Public blockchain ledger settlement as the system of record. Every listing, trade, and retirement is a transaction on a public blockchain (Polygon, with Base for Klima Protocol liquidity). There is no internal ledger to reconcile against the chain afterward, and no hidden intermediary between seller and buyer.
• Registry connectivity in both directions. Carbonmark is connected to ICR, Puro.earth, and EcoRegistry for credit transfers. Where a registry supports it, retirements are mirrored back to the host registry on a 1:1 basis, so the registry and the chain agree.
• Native machine-readability. The API is versioned with a published deprecation process, the docs are exposed as llms.txt for AI agents, and payment for agents happens over open protocols. Carbonmark is built to be called by software, not just browsed by people.

Why CDOP matters to this integration

Moving a carbon credit, which is essentially a digital asset, between two systems is a plumbing problem. Making sure the carbon credit means the same thing on both sides is a data problem, and it is the harder of the two.

Every registry has historically described projects in its own vocabulary. A country might be an ISO code in one system and a free-text field in another. "Project type," "methodology," and "status" can each have a dozen incompatible definitions. When CDOP's technical working group harmonized the schemas its members submitted, it found more than 1,600 unique data fields under location alone, across 15 distinct schemas. Anyone building a marketplace, a ratings model, or a corporate procurement tool has had to clean and re-map that data by hand.

CDOP (Carbon Data Open Protocol) exists to end that. It is an open-source data schema, published under an MIT license on GitHub as JSON Schema, that standardizes how carbon crediting projects and credits are described across markets, geographies, and activity types. It was launched in March 2025 and is co-chaired by the Global Carbon Market Utility (GCMU), Sylvera, RMI, and S&P Global Commodity Insights, building on earlier work by the Climate Action Data Trust, the ICVCM, and the World Bank's carbon market infrastructure working group. CDOP is a schema, not a registry, a policy framework, or a trading venue.

Two milestones so far:

Version 2.0 also introduced a standardized entity model and an auditable status history in place of a single overwritable status field. Migration from 1.0 to 2.0 is designed to require boundary-level changes rather than a re-architecture.

Where EcoRegistry and Carbonmark stand. EcoRegistry signed on at the Version 1.0 launch, already structures its project data to CDOP 1.0, and plans to move to 2.0. Carbonmark is aligning its own project and credit data model with CDOP Version 2.0. Our existing metadata already covers the core of CDOP's Project Approach and Details and Location Details modules, and we are extending it with CDOP's controlled vocabularies, ISO and UN location codes, and credit-level serial, vintage, and issuance-batch fields (the current mapping is documented on our data attributes page). The goal is that a project record arriving from EcoRegistry, ICR, or Puro.earth validates against the same schema and comes out of the API in one consistent shape.

When your procurement tool or your agent pulls project data over our API, it reads the same schema that a ratings agency or a registry reads.

Getting started

If you hold EcoRegistry credits, the fastest way to see how the connection works is to open your Carbonmark Portfolio, note your account's Base network address, and view EcoRegistry's native credit transfer tool from their trading page to import a small test quantity. Developers can explore the connected inventory through the Carbonmark API with a free sandbox key. If you are managing a portfolio at volume or want help structuring a listing strategy, talk to our Solutions Team.