Cap-and-invest offsets

In 2020, the Washington Legislature committed our state to becoming carbon neutral by 2050. Upholding this commitment will require that businesses invest in better processes and use cleaner energy to reduce their own emissions, but it can also help to invest in projects designed to combat global emissions outside of any one particular factory or industry – and that's where offset projects come in.

Sometimes just called "offsets," these are projects or programs designed to reduce the amount of greenhouse gases (GHGs) in the atmosphere. In Washington’s cap-and-invest program, offset projects must also provide direct environmental benefits to our state. You can learn more about the program's offset requirements below.

How do offsets work?

You may have seen offers from airlines and other businesses to "offset" the carbon footprint of a product you're about to purchase. Typically, this means you pay a little extra at checkout, and, in turn, the company invests those funds in a project that reduces the overal amount of GHGs in the atmostphere by the same amount that would be generated in the production of your purchase — whether that's a new handbag or a fraction of the emissions from a flight to Hawaii — meaning the net change in global GHGs is zero. 

The business isn't directly reducing its own emissions — that flight would still generate the same amount of pollution even if you cancelled your trip. Instead, the airline is balancing out the negative impacts of its emissions by funding a project that benefits the environment.

Of course, not all offset projects are created equal. If you "offset" a purchase as described above, for example, the business you are purchasing from is responsible for ensuring those funds are going to projects with verifiable results.

When it comes to offset credits that can be used in a regulatory system — such as Washington's cap-and-invest program, or similar programs in California and Québec — the agency responsible for administering the regulation is tasked with quality control. For cap-and-invest, the law provides sets several safeguards to ensure the integrity of offset projects, and it's our job to implement and uphold those standards.

Offsets under cap-and-invest

Questions about offsets?

Please contact our Offsets Team at with any questions about project registration and verification or for information about how to purchase and use credits.

For all other questions about the cap-and-invest program, or for media requests, please use the contact information at the bottom of this page.

Using offsets to cover emissions

Tribal offset projects

Offset projects on tribal lands are developed in the same way as non-tribal projects. As with non-tribal offset projects, offset projects on tribal lands must be listed with an approved offset-project registry, follow one of the 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. 

Project developer and registry resources

We will add new forms to this tab as they are developed. If you have any questions about these forms or listing requirements, please contact our Offsets team at

Approved registries

We will add new forms to this tab as they are developed. If you have any questions about these forms or registration requirements, please contact our Offsets team at

The following trainings were held in May 2023. To request a link to the recording and a copy of the slides, please email us using the links below.

Using offset credits for compliance in the cap-and-invest program 

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.

Request the Using Offset Credits for Compliance training

Developing offset projects in the cap-and-invest program 

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.

Request the Developing Offset Projects training

Please remember that offset project developers must have active accounts in the Compliance Instrument Tracking System Service (CITSS) in order to sell offset credits in the cap-and-invest marketplace. You can find all the information, trainings, and other resources needed to complete this process on our Auctions trainings and resources page.

For questions about your CITSS application process, please contact