What must the designating official do immediately upon revocation of DD Form 285?

The correct action upon the revocation of DD Form 285 is to notify in writing the servicing postal activity. This is crucial because the servicing postal activity needs to be made aware that the individual is no longer authorized to hold the privileges associated with the DD Form 285. This written notification serves as an official record that the revocation has taken place, ensuring that security and access protocols are enforced.

While it might seem that notifying the individual directly is important, the responsibility lies with the designating official to ensure that the postal activity is updated to maintain control over sensitive data and access. Additionally, submitting a new request or filing the form away would not reflect the immediate need to inform relevant postal operations about the change in status, thereby maintaining the integrity of the mailing and handling systems.