When do I have to be certified by? Ontario College of Teachers April 24, 2020 16:18 When do I have to be certified by? You must apply for, and be certified by December 31, 2023. Related articles Who does it apply to? Are you able to mail out any documents? When do I have to write the test by? Are teacher candidates exempt from the other requirements? Is there an exemption for the practicum requirement? Comments 0 comments Article is closed for comments.