Unionized in Canada? Overtime Disputes Usually Go Through a Grievance, Not the Ministry

A collective agreement is a contract between your union and your employer, and it comes with its own dispute-resolution machinery: raise the issue, file a grievance, and — if it isn't resolved internally — escalate to labour arbitration. In a unionized workplace, this internal route is generally the forum for overtime and pay disputes arising under the agreement, rather than the individual statutory complaint an unrepresented employee would use. Your union is your vehicle: the grievance is filed and advanced through it, not by you alone.

The important reassurance: choosing this route does not lower the bar. An arbitrator interpreting your agreement still cannot award you less than the statutory floor, because the agreement itself cannot lawfully contract below it.

Whatever your agreement says, these minimums remain the ground the arbitrator builds on:

• Federal: overtime at 1.5× the regular rate for hours over the statutory threshold (Canada Labour Code, s. 174), plus holiday pay and 1.5× for hours worked on a general holiday (ss. 196–197).
• Ontario: overtime at 1.5× for hours over 44 in a week (ESA, s. 22), plus public holiday pay and premium pay at 1.5× (s. 24).
• Québec: a majoration de 50 % (1.5×) over 40 hours a week (LNT, arts. 52 and 55).

So the grievance can improve on these — claiming a night premium, a double-time rate, or a daily-overtime trigger your agreement grants — but it can never resolve below them. The statutory minimum is the arbitrator's floor.

The path is usually three moves:

1. Raise it with your union steward. The steward is your first contact and knows the agreement's procedure. Bring your reconciled hours and pay stubs.
2. File the grievance within the agreement's internal deadline. This is the step most likely to trip people up — see the warning below. The grievance sets out the hours, the calculation, and the clause you say was breached.
3. Escalate to arbitration if it isn't resolved. If the internal steps don't produce payment, the grievance proceeds to labour arbitration under the agreement, where an arbitrator decides.

Throughout, keep documenting: dates, figures, and correspondence. The reconciliation that supports an individual complaint supports a grievance just as well.

This is the critical part. A unionized overtime dispute is governed by two separate timelines that do not line up, and you have to respect both:

• The agreement's grievance deadline. Collective agreements typically require a grievance to be filed within a short internal window — often measured in days or weeks from when the issue arose or should have been known. These are frequently much shorter than the statutory recovery windows, and missing one can bar the grievance regardless of the merits.
• The statutory recovery window. Separately, the statutory lookback still frames how far back wages reach: 24 months federally (Canada Labour Code, s. 251.1(1.1)), two years in Ontario (ESA, s. 111), and one year from each due date in Québec (LNT, art. 115).

These are different clocks. The grievance timeline can expire long before the statutory window does — so the fact that a Québec claim is technically within the one-year prescription is no comfort if your agreement required the grievance within, say, 30 days. Check your specific agreement's grievance timeline immediately, before anything else, and talk to your steward without delay.

For a unionized worker, the primary forum is labour arbitration under the collective agreement. The statutory routes — the Labour Program federally, the Ministry of Labour in Ontario, the CNESST in Québec — form the backdrop that sets the minimum standards, and they remain the reference point for the floor the arbitrator applies. (In Québec, note again: the tribunal for statutory disputes is the Tribunal administratif du travail — never "prud'hommes.") Which forum ultimately hears your dispute depends on your agreement and your situation, so raise it with your union early.