Suppliers who incorporate interest provisions into their invoices should take heed of the Alberta Court of Appeal’s decision in H2S Solutions Ltd. v Tourmaline Oil Corp., 2019 ABCA 373.

In H2S, the appellants had provided certain services to the respondents, and occasionally issued invoices. On the bottom of each invoice, the appellants included the following language:


The respondent argued that despite the wording on the invoices, there was no express or implied agreement between the parties to pay the invoice interest.

The Court agreed with the respondent, noting that a party cannot “unilaterally foist” the obligation to pay interest on another simply by adding such wording to its invoice, and sending it the other party (para 11).

The appellant relied heavily on the case Commercial Truck Equipment Corp. v Prairie Hydraulic Equipment, 2018 ABQB 218 to support its argument. In that case, the plaintiff charged interest to the defendant on its purchase orders. However, the Court distinguished Commercial Truck because the defendant had previously acknowledged the plaintiff’s invoice interest charges, and the plaintiff was also aware that it was an industry practice to include interest on invoices (para 12).

In contrast to Commercial Truck, the affidavit evidence provided by the respondent in H2S suggested that it had never expressly or impliedly agreed to pay invoice interest (para 17). As a result, the Court denied the appellant’s unilateral attempt to imposed invoice interest on the respondent.

The Court noted that in order to enforce interest charges, “…there must be some agreement to pay interest, whether oral, in writing, or implied by conduct or the natures of the parties’ business relationship or dealing concerning outstanding debt.” (para 11)

Given the H2S ruling, it may be prudent for suppliers to obtain a separate acknowledgement from their customers to pay interest. In principle, this could be achieved by attaching a separate sheet to the invoice which asks the customer to acknowledge that by accepting delivery, they are expressly agreeing to pay interest on any overdue invoice amounts.

I would like to thank Anuj Baxi for his assistance in writing this article.

Invitation for Discussion:

If you would like to discuss this blog in greater detail, or any other business litigation matter, please do not hesitate to contact Mohamed Amery.


Note that the foregoing is for general discussion purposes only and should not be construed as legal advice to any one person or company. If the issues discussed herein affect you or your company, you are encouraged to seek proper legal advice.