Income-tax rates: aggregation of net agricultural income affects tax computation and triggers surcharges for domestic companies. Income tax is charged at rates in the First Schedule with applicable surcharges; where net agricultural income exceeds a threshold it is aggregated with total income for rate determination but treated by a two step computation-tax on the aggregate and tax on the net agricultural income increased by a fixed exempt sum, the difference being the tax charged. Similar aggregation and reduction mechanics apply to withholding, collection and advance tax computations where specified, and surcharge rules for domestic companies apply as provided. Definitions for domestic company, insurance commission and net agricultural income are supplied.