When do you announce "Wrong Server!" to the second referee?

The correct timing to announce "Wrong Server!" is after the ball is contacted for the serve. This is crucial because at that moment, the act of serving has begun, and it confirms that the player identified as the server did not have the authorization to serve, either due to being the wrong player or because of a previous fault.

By waiting until after the ball is contacted, the second referee can effectively manage the game without interrupting the flow before any potential fault is committed. Announcing too early could lead to confusion or disrupt the rhythm of play, as the server may not be aware of the infraction until the action occurs. This ensures that all incidents of serving can be addressed clearly and appropriately without premature interruptions.