Over 50% of global greenhouse gas offsets were issued on APX registries last year.


Verified Carbon Units (VCUs)
Climate Reserve Tonnes (CRTs)
Emission Reduction Units (ERUs)
Registry Offset Credit (ROC)
Verified Emissions Reductions (VERs)
Certified Emission Reductions  (CERs)

APX is a leading infrastructure provider for environmental markets in greenhouse gases around the world. Users of these systems include all key market participants, from project developers, brokers, and corporations to NGOs and government organizations.

APX not only partners in technology, but invests in relationship-building to support the success of each of our carbon registry sponsor partners, personalizing our approach for each registry’s unique needs. APX operates as an extension of the sponsor organization, pairing an in-depth understanding of their programs with an expert awareness of industry trends and requirements. We constantly evolve with the industry, identifying strategic advances to help our partners meet market needs with technologically advanced, efficient, cost-effective and intuitive approaches.


As the premier carbon offset registry for the North American carbon market, the Climate Action Reserve encourages action to reduce greenhouse gas (GHG) emissions by ensuring the environmental integrity and financial benefit of emissions reduction projects. It establishes high quality standards for voluntary and compliance carbon offset projects, oversees independent third-party verification bodies, issues carbon credits generated from such projects and tracks the transaction of credits over time in a transparent, publicly-accessible system. It also serves as an approved Offset Project Registry (OPR) for the State of California’s Cap-and-Trade Program. The organization has worked closely with APX since the launch of its program. APX’s guidance and expertise have supported public accessibility of offset projects and credits under the Reserve and the transparency and rigor of the Reserve’s work to address climate change. The Reserve is a private 501(c)3 nonprofit organization headquartered in Los Angeles, California with satellite offices around the U.S.
Verra develops and manages standards that are globally applicable and advance action across a wide range of sectors and activities. Verra’s standards and programs are trusted by a broad range of stakeholders, provide innovative solutions to environmental and social problems, and work for people and the planet by supporting projects and activities that deliver a range of benefits to communities and their surrounding environments.
Climate Forward accelerates action on climate change by encouraging companies and organizations to proactively invest today in projects that mitigate future greenhouse gas (GHG) emissions. The program encourages a wide variety of innovative, creative investments in projects that will mitigate emissions from new types of economic activity, such as a new manufacturing facility, distribution center, housing development or construction project.

Under TREES, countries and eligible subnational jurisdictions can generate verified GHG emissions reduction credits by reducing their deforestation and degradation emissions, meeting comprehensive requirements for accounting and crediting; monitoring, reporting and independent verification; mitigation of leakage and reversal risks; avoidance of double counting; assurance of robust environmental and social safeguards; and the transparent issuance of serialized units on a public registry.

Founded in 1996 as the first private voluntary greenhouse gas registry in the world, ACR believes that climate change will have a profound impact on the poorest populations around the world and that markets are the most effective path to reduce emissions. As a pioneer in harnessing the power of markets to improve the environment, ACR has set the bar for offset quality that is the market standard today and continues to lead market innovations.

The Massachusetts Carbon Allowance Registry tracks allowances for large power plants in Massachusetts for purposes of reducing CO2 Emissions from Electricity Generating Facilities. Administered by MassDEP, the Allowance Registry enables Designated Representatives to register their facilities, receive or transfer allowances, and manage their allowance holdings.