You must be 18 years old to register with RECO as a real estate salesperson in Ontario. There is no upper age limit — RECO regularly registers people in their 60s and 70s.
The Humber pre-registration program does not have its own age minimum. A 17-year-old can enrol in Course 1 and complete coursework before turning 18. Many students do this to get ahead, but you cannot register with RECO and begin practising until your 18th birthday.
Practically, the path looks like this for young students: enrol in Humber at 17, complete Courses 1-5 plus Simulations through your 17th and 18th years, and register with RECO immediately on or after your 18th birthday with brokerage sponsorship lined up.
Note that the Humber-to-RECO eligibility window is 12 months after Course 5 completion. If you finish Course 5 at 17 and turn 18 within that 12-month window, you can register normally. If 12 months elapse before you turn 18, you would need to retake Course 5 — which is rare but possible for very young finishers.
There is no education requirement beyond the Humber program. A high school diploma is not required by RECO, although most brokerages prefer to hire candidates who have completed high school for client-facing roles.