This is a real, dated rule with a specific headcount test — not a general principle. Getting the threshold and the counting method right matters more than the general idea.
Short answer
Yes, for employers that employ 25 or more employees on the day a publicly advertised job posting goes up. Since January 1, 2026, Ontario's Employment Standards Act requires such a posting to include “a statement disclosing the employer's use, if any, of artificial intelligence to screen, assess or select applicants for the position.” Below that headcount, the requirement doesn't apply.
The count is of people, not full-time equivalents: “if an employer employs 20 part-time employees and 5 full-time employees, they employ 25 employees.” All of an employer's Ontario locations are added together, related employers treated as one employer under the ESA are aggregated, and the count includes probationary staff, some trainees, employees on leave, and fixed-term employees. A temporary help agency's assignment employees count toward the agency's own threshold, not the client business using them. The Crown, Crown agencies and Crown-appointed bodies are excluded entirely.
The required disclosure is narrow: a statement that AI is or isn't being used to screen, assess or select applicants for that specific position. It doesn't require naming the vendor or tool, describing how the system works, or obtaining applicant consent — and it sits alongside two other new requirements in the same posting: a statement of the expected compensation range, and a statement of whether an actual vacancy exists. All three landed in Ontario job postings on the same date, as part of the same set of amendments.
A related, separate obligation applies after an interview: the employer must tell an interviewed applicant, within 45 days of their (or their most recent) interview, whether a hiring decision has been made — and must keep every version of the job posting, and the information given to each applicant, for three years. Ontario's separate requirement that employers give every new hire a copy of the ESA information poster within 30 days of hiring is the older, more general version of the same instinct: put the basic rules in the employee's hands rather than leaving them to ask.
See also: what this disclosure duty does and doesn't require once a candidate is actually screened, why the ESA defines artificial intelligence at all.
Writing an accurate, defensible disclosure statement once a screening tool is actually in use is operations work — ai-operations covers it.
