Article 39 establishes the core charging principle of the Oman Income Tax Law. It mandates that tax shall be charged for every tax year on the taxable income that accrues to a taxpayer during that year. The specific rates at which this tax is calculated are determined according to the various provisions found throughout the Law. This Article provides the legal link between the derivation of income and the statutory obligation to pay tax, serving as the primary 'charging section' for domestic and resident entities.