A more thorough explanation:

Definition: A bordereau is a report that provides information about reinsured risks. It is usually sent by a cedent to a treaty reinsurer and includes details such as the underlying insureds, the types of risks covered, policies, and dates of loss. It can also refer to a detailed note of account.

Examples:

• A cedent sends a bordereau to a treaty reinsurer every quarter to report on the reinsured risks.
• A bordereau of accounts payable is a detailed list of all the money owed by a company to its suppliers.

The first example illustrates how a bordereau is used in the context of reinsurance. The cedent provides important information to the treaty reinsurer to help them understand the risks they are reinsuring. The second example shows how a bordereau can be used in accounting to keep track of money owed to suppliers.