JONK v MERCIER, 2026 ABKB 674

This case involved the costs portion of a family law dispute between Mercier (the “Defendant”) and Jonk (the “Plaintiff”), with each party claiming substantial success and seeking costs against the other. Justice Marion highlighted that substantial success, rather than absolute success, governs costs in family matters and that costs generally follow the overall result rather than being apportioned issue-by-issue. In assessing substantial success, the Court considered quantitative and qualitative factors, including the parties’ success on the various claims, the complexity of the issues, the monetary significance of the results, and the parties’ positions at trial against the results.

The property distribution was the principal issue in this case, and the result fell between the parties’ competing economic positions. The Plaintiff obtained an Award but received substantially less than claimed, while the Defendant achieved an unequal distribution in the Defendant’s favour but did not avoid distribution altogether. The parties similarly achieved mixed success on partner support because the Plaintiff obtained support, but in an amount significantly below the amount claimed, while the Defendant reduced but did not eliminate liability. Marion J. therefore found that neither party achieved substantial success and that the overall result reflected mixed success.

Applying the factors in Rule 10.33, the Court considered the Trial’s complexity, the financial significance of the issues, the parties’ relative success, and their litigation conduct. The Defendant unnecessarily prolonged the Trial by refusing to admit an adult interdependent partner relationship, while the Plaintiff’s reckless or dishonest testimony constituted a material factor against the Plaintiff and supported reducing any costs to which the Plaintiff might otherwise have been entitled. However, the Court concluded that awarding the Defendant costs because of the Plaintiff’s testimony would not be a proportionate response.

The Plaintiff made a Settlement Offer. However, it had not been left open for 2 months, as required for Formal Offers to Settle by Rule 4.29. Further, the Plaintiff had not proven that the Judgment put the Defendant in a worse position than her offer once the necessary adjustments were made.

The offer remained relevant pursuant to Rule 10.33(2)(h), however, because even offers that fail to comply with the Rules are relevant to costs if they are bone fide attempts to settle. The Plaintiff’s offer was a substantial and bona fide attempt to compromise the Plaintiff’s Trial position and would have provided the Defendant with a costs advantage by avoiding the Trial.

Weighing the mixed success, the parties’ unsuccessful positions, the Defendant’s unreasonable position on the adult interdependent partner issue, the Plaintiff’s reckless or dishonest testimony, and the Plaintiff’s Settlement Offer, Marion J. ordered each party to bear their own costs of the Action. Because neither party succeeded on the costs submissions, each party was also required to bear their own costs of the costs determination.