Postal Codes were introduced in Pakistan on 1 January 1988 to speed sortation and delivery. These codes are for the delivery post office in whose jurisdiction the address falls. For example, for the entire Defence Housing Authority (DHA) area (all 8 phases), Karachi, the delivery code is 75500. This code is not meant for the main DHA including post office's attached branch office. That code is +1 i.e. for DHA, the code is 75501. Another example is Lawrence College PostOffice, whose delivery code is 47114. In that case, its attached branch office of +1 is 47115.
Moreover, Azad Kashmir has also been post coded to Pakistani standards, but post code sequence 00010 to 12991 has been deliberately left blank pending a final resolution of Kashmir issue.
Pakistan Post office is one of the oldest government departments in the South Asia. In 1947, it began functioning as the Department of Post and Telegraph. In 1962 it was separated from the Telegraph & Telephone and started working as an independent.
The following is the list of some of the post codes within the country. GPO stands for General Post Office, the main post office in the city. For larger cities (Karachi and Lahore), there are a numbe r of GPOs; however the main one is the only one which has just the city's name attached to it (Karachi GPO and Lahore GPO). When evening postal services are offered, the name changes to NPO (Night Post Office).