Presumptive taxation simplifies reporting by allowing small taxpayers to declare income at prescribed rates and avoid detailed bookkeeping. The presumptive taxation framework permits eligible small taxpayers to compute taxable income on an estimated basis by declaring income at prescribed rates and, in turn, be relieved from maintaining regular books of account. Separate presumptive regimes apply to small resident businesses, resident professionals, goods carriage operators, and specific non-resident or foreign activities, each subject to eligibility conditions and statutory computation rules.