# Using dead-letter queues to capture encrypted event errors in EventBridge
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If you configure customer managed key encryption on an event bus, we recommend that you specify a dead-letter queue (DLQ) for that event bus. EventBridge sends custom and partner events to this DLQ if it encounters a non-retriable error while processing the event on the event bus. A non-retriable error is one where user action is required to resolve the underlying issue, such as the specified customer managed key being disabled or missing.
+ If a non-retriable encryption or decryption error occurs while EventBridge is processing the event on the event bus, the event is sent to the DLQ for the *event bus*, if one is specified.
+ If a non-retriable encryption or decryption error occurs while EventBridge is attempting to send the event to a target, including input transformations and target-specific settings, the event is sent to the DLQ for the *target*, if one is specified.

![A non-retriable error during event bus processing, sent to the event bus DLQ.](http://docs.aws.amazon.com/eventbridge/latest/userguide/images/cmkms-bus-dlq_eventbridge_conceptual.svg)


For more information, including considerations when using DLQs, and instructions on setting permissions, see [Using dead-letter queues](eb-rule-dlq.md).