Overseas nationals who stay for less than a year should pay income tax on any earnings made on the mainland, state media reported a finance ministry official as saying. Earnings made outside mainland China should remain exempt, the unnamed tax official said. China introduced income tax in 1980, when few citizens had incomes considered taxable, leaving foreigners to contribute the bulk of income tax revenue. Both residents and non-residents are subject to income tax. Foreigners and Hong Kong, Macao and Taiwan residents staying in China for less than a year are classified as non-residents on the mainland and currently account for the majority of expats.