The University of Toronto is a tri-campus university. Course enrolment for undergraduate UTM and St. George courses begins later in the enrolment cycle than UTSC enrolment (refer to https://www.utsc.utoronto.ca/registrar/academic-dates for specific date).
You are expected to follow UTSC academic and financial deadlines regardless of where the course is being held. Academic dates on other campuses may vary - please refer to the appropriate campus Calendar to verify when classes begin and end, as well as the final exam dates.
Effective 2022 Fall, degree students may take a maximum of 10.0 credits in other arts and science undergraduate divisions at U of T. Failed/dropped courses will not count towards the 10.0 credit maximum.
You can view the full policy/rules in section 6C.8 of the Calendar: https://utsc.calendar.utoronto.ca/6-understanding-degrees-programs-and-courses#6C
Students should check the relevant campus’ web timetable to determine whether the course has special enrolment controls or instructions. Students who do not have the specific course requirements listed in the Calendar’s course description risk being removed by the department; if you believe you have equivalent course prerequisites, contact the undergraduate department offering the course to have your eligibility checked.