Cap-and-Invest offset program

Under Cap-and-Invest, our state’s largest emitters must compete to buy “allowances” for every metric ton of greenhouse gases they emit. To reduce emissions, Ecology sells fewer allowances each year.

Offset credits are an alternative to allowances, but they can only be used for up to 8% of a company’s emissions. By purchasing offset credits, a business funds a project that reduces or removes greenhouse gases somewhere else, rather than buying allowances or reducing their own emissions.

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Use offset credits for compliance
View Ecology offset credit issuance table
View the offset rulemaking webpage

Images showing examples of forestry, livestock, and urban forestry offset projects

Offset projects include things such as reforestation, planting trees in urban areas, and capturing methane on dairy farms.

a graphic representation of removing, reducing, or avoiding greenhouse gas emissions, represented by grey clouds.

Offset projects reduce, remove, or avoid greenhouse gas emissions. In the Cap-and-Invest Program, emitters can use credits earned by investing in these projects to cover a small portion of their emissions. This encourages them to fund projects that help our shared environment.

Icons representing offset qualities: real, permanent, quantifiable, verifiable, and enforceable.

Offset projects must meet strict criteria to ensure they're actually providing environmental benefits. The CCA requires that offset projects must result in greenhouse gas reductions that are real, permanent, quantifiable, verifiable, and enforceable.

What are Cap-and-Invest offset credits?

Cap-and-Invest offset credits are generated by Ecology-approved projects that reduce or remove greenhouse gas emissions.

Each offset project must meet strict criteria that ensure results are verifiable and lasting and that it benefits local communities in Washington. Once a project has met these criteria, known as “protocols,” Ecology issues credits for every ton of greenhouse gases reduced. These credits can then be bought and sold between businesses in the Cap-and-Invest Program.

Offset credits are "under the cap," meaning we reduce the number of allowances we issue by the number of offset credits to keep emissions reductions on track. Ecology also has the authority to reduce the number of offset credits that can be used by a business if we determine that it contributes substantially to air pollution in an overburdened community.

Types of offset projects

So far, Ecology has approved protocols for four different types of offset projects:

Destruction of Ozone Depleting Substances Protocol: Projects that extract and destroy chlorofluorocarbons and hydrochlorofluorocarbons, which are super potent greenhouse gases typically found in commercial and industrial air-conditioning units and refrigerators. For full details, see the Ecology’s Ozone Depleting Substances Protocol, July 2025.
U.S. Forest Protocol: Reforestation, avoided conversion (conserving a forest under threat), and improved forest management projects (geared toward working forests). Ecology initially adopted California's U.S. Forest Protocol and is in the process of updating this protocol through rulemaking.
Urban Forest Protocol: Planting and maintaining trees in urban areas. Ecology adopted California’s Urban Forest Protocol.
Livestock Protocol: Capturing methane on dairy or swine farms by installing specialized "digester" tanks. Ecology adopted California’s Livestock Protocol.

Updating our offset protocols

Ecology regularly updates offset protocols based on the best available science and public input through the rulemaking process.

Current protocol revisions and development opportunities:

U.S. Forest Protocol: Ecology is in the process of considering revisions to our adopted U.S. Forest Offset Protocol via rulemaking. More information can be found on the U.S. Forest Offset Protocol rulemaking page.
Blue Carbon Protocol: We’re considering the feasibility of the development of a Blue Carbon offset protocol. Information about this is available on our Blue Carbon Exploratory Working Group page.

Using offset credits for compliance: Guidance for market participants

Businesses may use offset credits to cover a portion of their compliance obligations under the Cap-and-Invest Program. In the first four-year compliance period (2023-2026), emitters can generally cover up to 8% of their emissions with offset credits through a combination of general offset credits (up to 5%) and credits from projects on federally recognized Tribal lands (up to 3%).

This is reduced to a total of 6%, with 4% from general offset credits and 2% from projects on Tribal lands, starting in the second compliance period (2027-2030 and onward).

Details about limits can be found in the Climate Commitment Act Program rule.

Unlike allowances, offset credits are not bought nor sold at quarterly auctions. Instead, credits are bought and sold directly between program participants.

You must have an approved account in the Compliance Instrument Tracking System Service (CITSS) to purchase offset credits, and, once your account is approved, you can buy them directly from project developers or from other market participants, just like stocks and bonds.

At this time, credits from California can't be transferred. Only credits issued in Washington can be used to cover Washington emissions from Washington businesses.

If Washington's program were to link with the shared market in California and Québec, then we would expect to have more opportunities for transferability of credits between programs. However, Washington law directs us to undergo a robust, criteria-based public process to determine whether linkage would be beneficial to the state. This process is currently underway, and you can learn more about linking and what the law directs us to consider on our Linkage webpage.

Generating offset credits: Guidance for project developers, verifiers, and registries

To be issued offset credits, projects must:

Meet the criteria listed in one of our four offset protocols
Demonstrate direct environmental benefits to the state
Be listed with an approved offset project registry
Be verified by an independent third-party

The resources and forms below are available to help project developers, verifiers and registries fulfill these requirements. If you are looking for an offset form that is not linked in one of the tabs below, please reach out to CCAOffsets@ecy.wa.gov.

Ecology offset credit issuance table

The Ecology offset issuance table provides details on projects that have been issued Ecology offset credits under the Cap-and-Invest Program. This table is updated as offset credits are released.

Offset project operators registered as general market participants in Washington’s Cap-and-Invest Program under WAC 173-446-055(1)(a)(ii) can't participate in auctions or hold allowances.

Starting March 19, 2025, we began distinguishing offset project operators from other general market participants in our quarterly CITSS Registrant Reports.

Offset project operators registered as general market participants will continue to receive offset credits issued by Ecology for approved offset projects and can sell those offset credits in the secondary market. 

Washington's offset market is distinct from the California's Air Resources Board (CARB) offset market, and offset credits issued in Washington's market are unique and non-transferable to CARB's market.

As such, verifications completed for the development of an ozone depleting substances project in CARB's program don't count toward the maximum six out of nine project verifications completed by the same verification body or verification team member in Washington's market.

WAC 173-446-535(2) states that for ozone depleting substances projects:

Neither a verification body nor an offset verification team member may conduct offset verification services for more than any six out of nine consecutive offset projects developed by the following:
- Any given offset project operator
- Any authorized project designee on behalf of such an offset project operator
- Any technical consultant(s) used by the offset project operator or its authorized project designee(s).

This guidance applies only to the treatment of offset project verifications in Washington's Cap-and-Invest Program and doesn't impact treatment of offset project verifications in California's Cap-and-Trade Program.

The CCA requires that offset projects must result in greenhouse gas reductions that are real, permanent, quantifiable, verifiable, and enforceable. And the reductions must be in addition to those already required by law. All offset credits used for compliance in Washington’s Cap-and-Invest Program must demonstrate direct environmental benefits to the state.

In addition, offset projects registered in the Cap-and-Invest Program must be verified by an independent third party before credits can be issued.

You can read more about the requirements for offset projects under the CCA in the Cap-and-Invest Program rule.

Offset projects on Tribal lands are developed in the same way as projects on non-tribal lands: they must be listed with an approved offset-project registry, follow one of our four adopted offset protocols, and be verified by an approved third party.

We offer a Tribal Carbon Offset Assistance Grant program to help federally recognized Tribes in Washington assess the feasibility of a carbon offset project.

The forms below should be completed by an offset project operator or authorized project designee and submitted to the designated parties.

Project listing applications

Please note that an entity's CITSS registration process must be completed prior to listing an offset project with an Ecology-approved offset project registry.

Offset project data reporting forms

Additional forms

Project developers must have their offset project data reports verified by an independent third-party verifier. A list of accredited verification bodies and verifiers can be found at Approved Offset Verifiers and Verification Bodies in the Washington State Cap-and-Invest Program.

Verification bodies and verifiers can apply for accreditation by filling out and returning the forms below to CCAOffsets@ecy.wa.gov.

Project verification forms

The contracted verifiers can use the following forms are to fulfill verification service requirements.

Offset projects under the Washington Cap-and-Invest Program must be listed with one of the following approved offset project registries.

Trainings

Ecology offered trainings for market participants and project developers in May 2023. Please click the drop down for recordings of the trainings.

This training walks through the process, timeline, and requirements for developing an offset project in the Cap-and-Invest Program. We discuss the four offset protocols adopted by Ecology, as well as the process to determine whether or not an offset project provides direct environmental benefits to Washington. Third-party verification requirements and the first steps to begin listing an offset project in the Cap-and-Invest Program are also covered.

Watch the Developing Offset Projects training

This training walks through the process and considerations for using offset credits for compliance in the Cap-and-Invest Program. We cover the basic requirements for offset projects under the program, as well as the offset credit usage limits for covered entities. Considerations for offset credit procurement, such as invalidation, reversal, and direct environmental benefits to Washington are also discussed.

Watch the Using Offset Credits for Compliance training

Contact information

Cap-and-Invests offset program questions
CCAOffsets@ecy.wa.gov
Climate Commitment Act questions
CCAQuestions@ecy.wa.gov

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