Letters rogatory (letters of request) are formal asks from one court to another for assistance in gathering evidence from a non-party located abroad. A U.S. district court, for example, may ask the Ontario Superior Court of Justice to compel documents or testimony from an Ontario resident or company. In Canada, this assistance is grounded in comity but ultimately discretionary. The receiving court applies Canadian standards and will not simply rubber-stamp a foreign request.
The Governing Framework
Canadian courts approach enforcement through a set of non-exhaustive “guideposts” articulated in Lantheus and affirmed in Perlmutter. In Ontario, judges consider: (1) whether the evidence is relevant to issues actually in dispute; (2) whether it is necessary for trial, not merely investigatory; (3) whether it can reasonably be obtained elsewhere, particularly from parties to the foreign action; (4) whether enforcement would offend Canadian public policy or sovereignty, including privilege; (5) whether the request is specific rather than open-ended; and (6) whether the order would impose an undue burden on the Ontario witness. These factors are applied flexibly but with increasing rigour, especially when the target is a true non-party.
Canada is not a party to the Hague Evidence Convention, and enforcement proceeds under federal and provincial statutes and the common law. Practically, this means a two-step process: the foreign court issues the letter of request, and the applicant then seeks an enforcement order from the relevant superior court in Canada. The moving party bears the burden to establish that the evidence meets Canadian standards for trial-use necessity and proportionality.
Undue Burden and Who Pays
Ontario courts generally order that applicants pay near-full indemnity for reasonable compliance costs for true non-parties, but will not write a blank cheque.
Two practical approaches recur. When the scope is reasonably clear, courts often fix a single capped amount for future compliance after interrogating rates, projected hours, vendor fees, and review volumes.
Illustrative caps include Scoular v. Detlefsen (a $20,000 all-inclusive cap on compliance) and Advance/Newhouse (a fixed $6,000 for counsel’s preparation and attendance).
Recent costs rulings demonstrate disciplined scrutiny. In Svoboda v. ModiFace (costs), the court accepted the principle of full indemnity for reasonable future compliance but reduced premium hourly rates it found “simply unreasonable,” fixing a $50,000 amount as fair and proportional. On the litigation-costs side, the same decision cut a substantial-indemnity bill of roughly $185,000 to $100,000, noting that a successful non-party cannot over-litigate and expect the other side to pay for disproportionate effort.
[26] As noted by Leach, J. in Aker Biomarine, costs awarded on a full indemnity basis are still subject to the overriding principle of reasonableness. In my view, costs in the all-inclusive amount of $50,000 are reasonable under the circumstances with respect to future compliance with my order.
When scope is uncertain—common in e-discovery—the decision of Kimmel J. in Cunix v. Sol Global Investment Corp is instructive: reaffirming that a true non-party should not be out of pocket for reasonable compliance and that applicants should not be handed a blank cheque, the court imposed a time-boxed, multi-stage process that begins with immediate production of discrete, low-friction records, proceeds to limited scoping searches across selected custodians to generate objective hit-counts and false-positive data, and then uses that data to anchor a negotiated budget and cap; if agreement fails, the parties return to the same judge for tailored directions—an evidence-driven progression that enforces proportionality, disciplines cost, and ensures efficient judicial supervision.
Practical Guidance for Both Sides
For applicants, success turns on localized, trial-focused precision. Draft the foreign request and the Ontario materials to show unique necessity and non-obtainability, tie each category to intended trial use, specify custodians and date ranges, and propose either a fixed cap supported by evidence or a staged regime with a right to return to the court. Offer to underwrite reasonable non-party counsel time for preparation and attendance and vendor expenses, subject to a sensible cap.
For non-parties, the most effective resistance is evidentiary, not rhetorical. File detailed affidavits quantifying time already spent, projected effort, system constraints, vendor pricing, and confidentiality or privilege concerns, and propose narrower substitutes where appropriate (for example, obfuscated builds rather than raw source code). Ask the court for sequencing and a cap, and expect scrutiny of premium rates unless the work truly demands them. Where party-side sources have not been exhausted, insist on that hierarchy; Cisco confirms the point.
Conclusion
Comity opens the door, but Canadian discretion decides who enters. Ontario courts now demand a clear, trial-bound rationale, demonstrated exhaustion of party-side avenues, specificity in scope, and a defensible plan for costs. Applicants who arrive with data and proportional solutions are most likely to obtain assistance. Non-parties who document burden, privilege, and commercially sensitive impacts—and who propose workable alternatives—can meaningfully narrow or defeat requests. In either posture, the winning strategy is the same: precision, proportionality, and proof.
