LETTER OF INSTRUCTIONS NO. 605

: All Heads of Departments of the National Government and Local Governments, as well as Government-owned and/or controlled Corporations.
: All heads of departments must circularize their officials and employees to regularly use the proper postal code numbers on both official and private mail matters.
: Postal code numbers of both the sender and the addressee should be placed on the face of the envelope.
: Arabic numbers should be used to write the postal code inside frames or squares.
: The ink must be black, blue, or blue-black. Pencil or other ink colors cannot be used as the new mail sorting machines cannot read them.
: Postage stamps should be affixed on the upper right-hand corner of the face of the envelope.
: One should secure postal code numbers from the nearest post office.
: They may be sent in the usual manner but should bear the new postal code numbers, and they shall be sorted manually.
: Mass media facilities should periodically include reminders about the proper use of postal code numbers on all mail matter as part of their public service programs or features for one year from the issuance of the instructions.
: The intended result is the successful implementation of the new postal code system and improvement of mail service in the Philippines.