Tiers décideur (third-party decision-maker)

The tiers décideur is the accredited third-party decision-maker at the heart of Quebec's new fast-payment and dispute-resolution regime for public construction. It was created by the Règlement sur les paiements et le règlement rapides des différends en matière de travaux de construction (chapter C-65.1, r. 8.001, Décret 941-2025), made under the Loi sur les contrats des organismes publics as amended by the 2022 Act strengthening public procurement integrity (2022, chapter 18).

What it is

Under Chapter III of the regulation, a party to a dispute over a public construction contract — or over a public subcontract attached directly or indirectly to it — can refer the dispute to a tiers décideur drawn by lot from an accredited registry, following a designation process the regulation details, including recusal rules where there are serious grounds to doubt the decision-maker's impartiality. The disputes that qualify include, notably, the validity of a payment demand or whether a payment refusal, deduction or retention complies with legal and contractual requirements. The decision-maker must ensure the fairness of the process and respect proportionality, and can be removed on the request of an accrediting body.

How it fits the payment regime

The tiers décideur regime is the dispute-settlement half of a broader chapter of the regulation that also sets payment deadlines down the contracting chain — for public bodies, payment by the last day of the month in which the payment demand is received, with shorter deadlines and per-level additions of 5 days for each additional subcontracting tier beyond two — together with rules on payment refusals, deductions, retentions and interest. The regulation phases in by category of contract: its chapters on payments and on the tiers décideur do not apply to contracts already in progress, or arising from calls for tenders launched, before the applicable dates, and it replaces the earlier pilot provisions on third-party decision-making that had been integrated into the construction contracts regulation (C-65.1, r. 5).

What it means for vendors

Quebec public construction now offers a fast, regulated track to resolve payment fights without ordinary litigation: short day-count deadlines (computed excluding the first day and counting holidays), a lottery-based designation of an accredited decision-maker, and explicit protections against splitting a dispute to multiply interventions or otherwise abusing the right of recourse. Track which contract category and which in-force date applies to your project, because the regime's chapters I and II (articles 1 to 33) and sections I and II of chapter III (articles 34 to 76) attach by category and in-force date, not automatically to every contract.

Common questions

Is the tiers décideur the same as Ontario adjudication?

It is Quebec's analogue: both give construction parties a fast interim dispute process. The Quebec version lives in its own regulation under the LCOP, uses an accredited registry and lottery designation, and applies to public contracts and their subcontracts rather than to all construction contracts under Ontario's Construction Act.

What disputes can go to the tiers décideur?

Disputes arising between the parties to a covered public contract or subcontract — including, notably, the validity of a payment demand and the conformity of a payment refusal, deduction or retention with legal and contractual requirements — subject to the regulation's exclusions.

Related definitions

LCOP · Adjudication (Ontario) · Notice of non-payment (Ontario) · Progress payment · AMP