Can a Comma Decide Coverage?
Sometimes the difference between coverage and no coverage comes down to a single comma.
Insurance policies often contain listed items with a trailing modifier at the end. However, disputes can arise in deciding whether the modifier at the end of a list applies to all of the listed items, or only the last item in the list.
Consider the following definition within an insurance policy:
Pollution Conditions means contaminants, debris, leaks, and spills arising from the insured’s operations.
The issue may arise whether the modifier, “arising from the insured’s operations”, applies only to “spills” or whether it must apply to all of the listed pollution items including “contaminants, debris, [and] leaks” to trigger coverage under the policy.
Canadian Courts interpret insurance contracts by starting with the text, read in its ordinary and grammatical sense in the context of the policy as a whole. [1] Where the clear language of the policy is unambiguous, no further analysis is needed. [2]
In determining a policy’s clear language, Ontario Courts interpret punctuation, particularly commas, in contract clauses using established grammatical rules in addition to the overall context and purpose of the contract.
The “last antecedent rule” suggests that if there is no comma before a modifier at the end of a list, the modifier applies only to the last item in that list.[3]
The “series qualifying rule,” by contrast, indicates that if a comma is present before the modifier, it applies to all items in the preceding list.[4]
Following the last antecedent rule in the example above, the Courts would likely find that the modifier, “arising from the insured’s operations” applies only to “spills” because there is no comma immediately before the modifier at the end of the list. On that reading, contaminants, debris, and leaks would not need to arise from the insured’s operations to trigger coverage.
Insert a comma, however, and the analysis flips. The modifier would apply to the entire list, narrowing coverage significantly.
These rules are helpful, but they may not always be determinative. Courts have stressed that the existence or omission of a single punctuation mark cannot dominate the interpretation of a contractual provision as this would undermine the Supreme Court’s direction to adopt a “practical, common-sense approach not dominated by technical rules of construction.”[5]
Courts are not rigidly bound by these rules. In statutory interpretation, Courts have declined to apply the last antecedent rule where it would produce an interpretation inconsistent with the scheme of the legislation.[6]
In the insurance context, however, Ontario Courts have shown a willingness to rely on punctuation where the wording is otherwise clear, sometimes treating the presence or absence of a comma as determinative.[7]
For insurers and coverage counsel, the takeaway is straightforward: punctuation is not cosmetic. Small drafting choices can materially expand or restrict coverage. When assessing a policy, it is worth paying close attention to how lists are structured and whether a modifier is meant to apply broadly or narrowly. In some cases, coverage really can turn on a single comma.
[1] The Jewish Theological Society of Canada o/a Camp Ramah in Canada v. Arch Insurance Canada Ltd., 2025 ONSC 374 (CanLII)
[2] Ledcor Construction Ltd. v. Northbridge Indemnity Insurance Co., 2016 SCC 37 (CanLII) [Ledcor v Northbridge] at para 49.
[3] Austin v Bell Canada., 2020 ONCA 142 (CanLII); see also Ruth Sullivan, Sullivan on the Construction of Statutes, 6th ed. (Markham: LexisNexis, 2014), at p. 470.
[4] Ibid.
[5] 1797472 Ontario Inc. v. Independent Electricity System Operator, 2024 ONCA 808 (CanLII); Sattva Capital Corp. v. Creston Moly Corp., 2014 SCC 53 (CanLII).
[6] Beaudin v. Travelers Indemnity Insurance Company of Canada, 2021 ONSC 1389, 10 C.C.L.I. (6th) 251 (Div. Ct.), at paras. 40-49, aff’d 2022 ONCA 806, leave to appeal refused, [2023] S.C.C.A. No. 40568; Joaquim v. Intact Insurance Company, 2023 ONSC 5120, 37 C.C.L.I. (6th) 201 (Div. Ct.), at paras. 19-24.
[7] 1088437 Ontario Inc. cob as Northmore Fuels v. GCAN Insurance Company et al., 2013 ONSC 7346 at para 12; Austin v Bell Canada., 2020 ONCA 142 (CanLII).