Intervenor information

Intervenors are individuals or groups who have our permission to actively participate in a public hearing about a utility’s application. Intervenors represent various customer groups such as low-income consumers, school boards and commercial and industrial customers. They also sometimes represent special interests such as environmental and conservation groups.

Intervenor Participation


Provided to intervenors to fund their participation in 61 OEB proceedings and consultations, including consumer groups, manufacturers, farmers, landowners, and indigenous communities.

How to participate

Follow a Proceeding - You can sign up to receive documents issued by the OEB in a particular proceeding by sending an email to the address below.

  • Be sure to include the case number for the proceeding you wish to follow. The case number can be found in the Notice of Application and follows this format: ‘EB-yyyy-####’
  • Note that not all documents related to the proceeding will be forwarded – only OEB issued documents. If you want to see documents other than those issued by the OEB, please use our Regulatory Document Search and enter the case number (EB-yyyy-####) of the proceeding that you are following.

Send a Letter of Comment - If you wish to comment on the proceeding, you may submit a letter of comment. The letter of comment will be considered by the Commissioners deciding the application.

  • Please reference the OEB file number (EB-yyyy-####) for the application in the subject line of your email or at the top of your letter. You must also provide your name, postal address and telephone number and, if available, an email address and fax number.

Use the contact information at the bottom of the page to follow a proceeding or send a letter of comment. You can also send a letter of comment using our online form.

Become an intervenor

Intervenors are interested groups or individuals who participate actively in the proceeding either by submitting evidence, arguments or interrogatories (written questions) or by cross-examining a witness or witnesses at an oral hearing. Intervenors may include customers and other affected individuals, consumer and trade associations, environmental and regional interest groups, and other public interest groups.

To see the mandate and objectives of frequent intervenors in OEB proceedings, as well as their membership and the constituency they represent, view the Annual Filings of Frequent Intervenors.

To request intervenor status, you must file a letter of intervention with the OEB and send a copy to the applicant. Unless the notice states otherwise, the letter of intervention must be filed/sent no later than 10 days after the publication or service date of the notice of hearing for the application. 

A letter of intervention must comply with Rule 22 of the OEB’s Rules of Practice and Procedure, and include, among other things: 

  • the application file number;
  • your contact information (name, address, telephone number, fax number, and email address);
  • a description of how you are, or may be, affected by the outcome of this proceeding;
  • the nature and scope of your intended participation;
  • if you represent a group, include a description of the group and its membership; and
  • whether you intend to seek an award of costs and the grounds for your eligibility. 

If you are considering applying for cost award eligibility, please refer to the OEB’s Practice Direction on Cost Awards. Your request should address the eligibility criteria in section 3 of the Practice Direction. The burden of establishing eligibility for a cost award is on the party applying for a cost award. A party found eligible for a cost award may not recover all the costs it claims. Consistency with the OEB’s tariff, the conduct of the party during the proceeding, and the reasonableness of the final cost claim will be among the factors considered by the OEB, as outlined in the Practice Direction.

Everything an intervenor files with the OEB, including the intervenor's name and contact information, will be placed on the public record through our website and the OEB Regulatory Document Search. 

If you already have a user ID, please submit your intervention request through the OEB's Filing Services. If you do not have a user ID, you may complete a user ID/password request form (pdf).

Parties must file their documents in searchable / unrestricted pdf format and use the document naming conventions and document submission standards outlined in the RESS Document Guidelines (pdf).

The OEB also accepts interventions by email at the address below.

All communications should be directed to the attention of the OEB Registrar at the address below and be received no later than 4:45 p.m. on the required date.

Ontario Energy Board
P.O. Box 2319
2300 Yonge Street, 27th Floor
Toronto ON  M4P 1E4
Attn: Registrar
Tel:  1-888-632-6273 (toll free)
Fax:  416-440-7656