Knowledge Centre

PEO publishes a variety of resources to assist licence holders in their roles and responsibilities, as well as guidance for applicants going through the licensure process.


Ontario professional engineers are part of a community of more than 87,500 PEO licence and certificate holders committed to enhancing the quality of life, safety and well-being in the province.

PEO’s Engineering Intern (EIT) program provides guidance and assistance to engineering graduates as they acquire the 48 months of acceptable engineering work experience, including annual reviews of experience.

As the regulator of engineering in Ontario, it’s PEO’s role to assure the public that licensed practitioners are competent to practise in their chosen discipline, and that they are taking responsibility for the outcomes of their work.

As Ontario’s engineering regulator, PEO relies heavily on its volunteers. More than 1,000 professional engineers, engineering interns and non-engineers volunteer their time each year on behalf of the association through their participation.

PEO's mandate, as described in the Professional Engineers Act, is to ensure that the public is protected and that individuals and companies providing engineering services uphold a strict code of professional ethics and conduct.

Online Learning Modules

PEO’s Online Learning Modules provide licence holders, volunteers, staff and applicants with various learning and development opportunities.

Practice Advice Resources and Guidelines

PEO offers a variety of practice advice resources to assist licence holders in providing professional and ethical engineering services.

Frequently Asked Questions

Known as " as-built drawings," these should not be sealed. Seals should be applied only in those cases where you or your delegate have visited the site, reviewed the project during construction, and have verified every change in detail. The changes must be clearly marked on the drawings and a note referencing the original sealed drawings should be attached. These documents are referred to as “record drawings” to distinguish them from “as-built drawings”. Record drawings verified in detail by the engineer and issued to a third party must be sealed.

The engineer's signature and the date the document was sealed, hand written within or beside the stamp, must always be included. Initials alone are not acceptable.

No. PEO members are not permitted to use, or refer to, their professional seals in company logos, advertising or other promotional materials.

Certain types of legal documents are required to be sealed. However, the professional engineer's seal is not appropriate for these purposes. Contracts and other legal business documents are sealed with a corporate seal if the business entity is a corporation. If not, signatures suffice. Professional seals are not to be used for this purpose. Certain documents, such as statutory declarations, must be sealed by a Commissioner for taking affidavits or a Notary Public in order to be valid. A Commissioner for taking affidavits is a person, such as a lawyer, MPP, municipal official or court official who is authorized to administer oaths or take affidavits. Notaries public are regulated by the Notaries Act. Persons, other than barristers and solicitors, wishing to be appointed as notaries must have their qualifications examined by a Superior Court judge. Only persons certified by a judge will be considered for the position and, if selected, are appointed by the Attorney General. Passport applications, birth certificate applications and other documents that identify professional engineers as suitable guarantors require only the guarantor's signature followed by the "P.Eng." designation.

Draft or uncompleted documents and documents of a non-engineering nature (business correspondence, sales brochures, passport and birth certificate applications, etc.) should not be sealed. Generally, preliminary documents should be not be sealed. However in some cases, such as when a client wishes to proceed with a portion of the work before the final drawings have been completed, this may be necessary. An example would be where an owner wants to commence construction of a building's foundation and obtains a permit limited to this work. In such cases, the design engineer must be careful when sealing the foundation part of the work. The engineer should try to limit the extent to which their seal is to be relied upon, and the extent to which they take responsibility for the content of the work. One way to do this would be by marking the documents "preliminary" and/or "not for construction," to indicate that construction can't proceed without further written approval of the design engineer.

Any final documents of an engineering nature such as drawings, specifications, reports, studies, etc., should be sealed. Ideally, all final drawings within an engineering branch should be signed and sealed by the design engineer for that branch and the approving or supervising engineer, but if only one signature and seal is used, it should be that of the approving engineer. Final drawings that cross disciplines should be sealed by each engineer in charge of the respective branches and the approving one. Final specifications prepared by the approving engineer must be sealed on the cover of the bound document. Because of the risk of sealed originals being copied and distributed without the engineer's knowledge, seals should not be applied to original master documents, only to copies. Drawings provided solely for your employer's use within the employer's domain do not need to be sealed (though if the work involves the practice of professional engineering it would have to be done by a P.Eng. or under a P.Eng.'s supervision).

The term "providing professional engineering services to the public" is used in conjunction with two specific regulatory issues mentioned in the Professional Engineers Act: the sealing of engineering documents and the need for a Certificate of Authorization. A P.Eng. is providing professional engineering services when s/he undertakes any of the activities considered to be within the practice of professional engineering for the benefit of an employer or 'the public'. For the purposes of all regulatory directives regarding engineering practice 'the public' is considered to be anyone other than him/herself or the professional engineer's employer. Therefore, a P.Eng. is providing professional engineering services to the public when the work is done for the benefit of an individual, corporation, government or other entity that is not the engineer's employer. Work done by a professional engineer solely for the employer's use within the employer's domain is not considered to be work done for the public even if the employer is a public institution such as provincial or municipal governments, school boards, or crown corporations. However, if the work involves the practice of professional engineering it must be done by or supervised by a P.Eng. even if it is solely for the employer's benefit.

Section 53 of Regulation 941 of the Professional Engineers Act states that "[e]very holder of a licence, temporary licence or limited licence who provides to the public a service that is within the practice of professional engineering shall sign, date and affix the holder's seal to every final drawing, specification, plan, report or other document prepared or checked by the holder as part of the service before it is issued." For more information, please see the Use of the Professional Engineer’s Seal guideline.

PEO does not have any affiliation with the iron ring. The iron ring is associated with the Ritual of the Calling of an Engineer and is administered to engineering students upon graduation at an Obligation Ceremony. You can find out more about the iron ring and how to obtain one by visiting

If a person uses the title “professional engineer”, or “engineer”, or any other occupational title that might lead to the belief that the person is qualified to practice professional engineering, or uses a seal that leads to the belief that the person is an engineer, PEO will prosecute the matter through provincial court. Fines for people found guilty can range from $10,000 for a first offence, to $50,000 for repeat offences.