 In line with its status as a major port and the country's largest metropolis, it accounts for most of Pakistan's revenue generation.According to the Pakistan Federal Board of Revenue's 2006-2007 year-book, tax and customs units in Karachi were responsible for 70.75% of direct taxes, 33.65% of federal excise tax, and 23.38% of domestic sales tax.Karachi also accounts for 75.14% of customs duty and 79% of sales tax on imports.