Liability policies usually show two numbers: a per occurrence limit and an aggregate limit. Contractors often focus on the first and overlook the second. For a snow business that can face several claims in one winter, both matter.
In short: the per occurrence limit caps what the insurer pays for any one incident. The aggregate limit caps what it pays for all incidents during the policy period.
Definitions
Per occurrence limit. IRMI describes it as "the maximum amount the insurer will pay for all claims resulting from a single occurrence, no matter how many people are injured." See our glossary entry.
Aggregate limit. IRMI describes it as a provision "limiting the maximum liability of an insurer for a series of losses in a given time period," for example a policy year. See the aggregate limit glossary entry.
Side by Side
| Per Occurrence | Aggregate | |
|---|---|---|
| Caps | One incident | All incidents in the policy period |
| Resets | For each new occurrence | At renewal |
| Typical question | Is one big claim covered? | What if several claims arrive in one season? |
| Where contracts mention it | Commonly | Sometimes, alongside the per occurrence figure |
How They Interact: An Illustration
Take the limits the Township of Otonabee-South Monaghan asked for in its facilities winter maintenance RFP: general liability of $5,000,000 per occurrence and $10,000,000 aggregate.
On a policy with those limits:
- One claim can be paid up to $5,000,000.
- Several claims in the same policy period can together be paid up to $10,000,000.
- Once $10,000,000 has been paid out in the period, the policy has no limit left until renewal, even though each new claim is under $5,000,000.
This is a simplified illustration. Real policies can differ: some limits include defence costs, some have separate aggregates for specific coverages such as products and completed operations, and deductibles apply. Read your own policy and ask your broker.
Why Aggregates Matter in Snow Removal
Snow contractors can face several slip and fall claims from one winter, across different sites, sometimes arriving months after the season ends. A contractor servicing many high traffic sites has more chances for multiple claims in one policy period than one clearing a few driveways.
Some policies also carry a separate completed operations aggregate. The OSM tender, for example, listed products and completed operations at $5,000,000 alongside the main limits. Ask your broker whether your completed operations coverage shares the general aggregate or has its own.
How Contracts Use These Limits
Some contracts specify only a per occurrence figure, such as the Bruce Grey Catholic District School Board template asking for $2,000,000 per occurrence. Others specify both, as OSM did. When a contract asks for a per occurrence limit you do not have, an umbrella policy is one way contractors meet it. See CGL vs umbrella and $2M vs $5M liability.
Also think about who else shares your limits. When clients are named as additional insured, claims against them under your policy can draw on the same limits.
Questions to Ask Your Broker
- What are my per occurrence and aggregate limits on each liability policy?
- Are defence costs inside or outside the limits?
- Is there a separate aggregate for completed operations?
- Does my umbrella sit over both the per occurrence and aggregate limits?
- Do my limits meet every contract I have signed?
General information only, not insurance advice. Coverage depends on policy wording.
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Sources
- IRMI: Per occurrence limit
- IRMI: Aggregate limit of liability
- Township of Otonabee-South Monaghan winter maintenance RFP
- Bruce Grey Catholic DSB snow contract template
Frequently Asked Questions
What is the difference between per occurrence and aggregate limits?
The per occurrence limit caps what the insurer pays for one incident. The aggregate limit caps the total for all incidents in the policy period.
What happens when the aggregate limit is used up?
The policy has no remaining limit for that period until it renews, even if each claim was below the per occurrence limit. Check your policy wording with your broker.
Do contracts ask for aggregate limits?
Some do. The Township of Otonabee-South Monaghan RFP asked for $5,000,000 per occurrence and $10,000,000 aggregate, while other contracts list only a per occurrence figure.