Definition - What does Other Insurance mean?
Other insurance refers to situations where more than one insurer covers the same asset or assets. Most types of insurance, except life insurance have "other insurance clauses." It is common for other insurance clause to state that where there is other insurance, the insurers will each pay out a portion of the claim.
Insuranceopedia explains Other Insurance
The portion of the loss that each insurer has to pay is usually proportional to the insured amount of the policy. However, this is not always the case. In fact, some other insurance clauses state that where a loss is covered by more than one insurer, one insurer has the full burden, and the other has zero obligation. The amount of money that other insurers must pay can vary from policy to policy and depends on the other insurance clause for the specific policy.