Income of any person including a company, accruing in or derived from Malaysia or received in Malaysia from outside Malaysia is subject to income tax. However, income received in Malaysia by any person other than a resident company carrying on business of banking, insurance or sea or air transport for a year of assessment derived from sources outside Malaysia is exempted from tax.

To modernise and streamline the tax administration system, the self-assessment system was implemented for companies, sole proprietor, partnerships, cooperatives and salaried groups and the assessment of income tax is based on a current year basis.