Pakistan’s Federal taxation was originally organised along the lines of Indirect & Direct taxes, resulting in two occupational groups viz.

The responsibilities of collecting sales tax and Federal excise on Domestic Transactions were transferred to the newly created Inland Revenue Service (IRS).

In the following year, a plan was instituted to build permanent offices for the port and Customs officials at Karachi.

The task was entrusted to G. Willet, the consulting architect to the Government of Bombay, who designed the new building as a semi-circular structure in the Victorian tradition.

It was the second oldest Collectorate in the country whose jurisdiction spanned the whole of the former West Pakistan, barring Karachi and Balochistan.