ZIP codes in the Philippines

In the Philippines, a ZIP code is used by the Philippine Postal Corporation to simplify the distribution of mail. While its function similar with the ZIP Codes used in the United States, its form and usage are quite different. Its use is not mandatory but highly recommended by the PhlPost. A ZIP code is composed of a four-digit number representing a locality. Usually, more than one code is issued for areas within Metro Manila, and a single code for each municipality and each city in provinces, with exceptions such as:

Davao City with eleven ZIP codes ;
Antipolo with six ZIP codes ;
Calamba, Cavite City, Dasmariñas, Mabalacat, Mariveles, and the Island Garden City of Samal with three ZIP codes each; and
Angeles City, Bacoor, Baguio, Bamban, Biñan, Capas, Floridablanca, General Tinio, Labo, Laur, Limay, Lipa, Los Baños, Lubao, Lucena, Majayjay, Muñoz, Palayan, Porac, Puerto Princesa, Sagay, San Jose del Monte, San Rafael, Santa Rosa, Santa Rosa, Silay, Sorsogon City, and Tagbina with two ZIP codes each.

Additionally, locations such as Basilio Fernando Air Base, Cesar Basa Air Base, Central Luzon State University, Clark Special Economic Zone, Mactan-Cebu International Airport, Francisco Bangoy International Airport, Laguna Technopark, Ninoy Aquino International Airport, Manila Domestic Airport, Philippine Military Academy, University of Mindanao, University of the Philippines Los Baños, and Villamor Air Base have one code each.
A bill currently in the House of Representatives is set to expand the ZIP code from a four-digit numeric system to a seven-letter alphanumeric code, more clearly encoding the region, city, and barangay.