What is the pro rata condition of average on an insurance claim?

The term "pro rata" is used to describe a proportionate distribution. In the insurance industry, "pro rata" means that claims are only paid out in proportion to the insurance interest in the asset; this is also known as the first condition of average. Pro rata is also used in bankruptcy claims, where an insolvent debtor's assets are divided proportionately among creditors based on the size of claims.

The pro rata condition of average can also be thought of this way: The insurer is only liable for the proportion of the loss that the amount of insurance under the policy bears to the actual cash value of the asset; the insured assumes all liability beyond that point.

Suppose that a homeowner takes out $200,000 worth of fire insurance on his home. The home is actually valued at $300,000. A fire subsequently breaks out in the home, causing $60,000 worth of damage.

If the fire insurance policy uses the pro rata condition of average, the insurance company is only liable in proportion to the level of insurance relative to the value of the property. Since the insurance only covers two-thirds the value of the property ($200,000 / $300,000), the insured can only recover two-thirds the cost of damage – $40,000, in this case ($40,000 / $60,000).

Most insurance literature identifies only two separate conditions of average. The first is pro rata, as described above. The second is known as a special condition of average, whereby under-insurance is not penalized unless the sum represents less than 75% of the at-risk value. Most policies with pro rata conditionality are buttressed with a special condition.