Registration as a Professional Engineer requires an undergraduate degree from an engineering program accredited by the Canadian Engineering Accreditation Board and four years of relevant and verifiable engineering experience. Applicants for registration who do not have an engineering degree or a degree from an accredited school are assessed examinations by APEGA. In Canada, individuals cannot represent themselves as engineers unless they are registered with one of the provincial/territorial professional associations as either an engineer or a P. Eng.
Pre-graduation Co-op work experience can count for up to 12 months of the four-year experience requirement. It is important to realize that each case is dealt with on its own merits. Some graduates will get 12 months credit, others will get less, and perhaps significantly less, than that. APEGA's Board of Examiners makes its decisions based on the acceptability of the claimed experience by supervisors who must provide this information directly to the Board.
You will not apply for professional registration until you believe you have the required four years of experience. If some of this experience comes from Co-op work terms that you completed three or more years before, will you remember what you did and who you worked for on these work terms? It is a good idea to keep a work term diary in which you log on a weekly or monthly basis the work that you have done. Don't forget to record your supervisor's name, address and phone number. Even if your supervisor moves prior to your applying for registration, this will at least give you a starting point to track this individual down.