Show INCOME TAX IN A NUTSHELL who single persons who had net incon ncoma w of 1000 or more or gross inconis ncoma of or more arid and married couples who had bad net income of 2500 or more or gross income of or more must file returns I 1 when the filing period begins I 1 january I 1 and ends march 15 1937 where collector of internal revenue for the district in which the person lives or has his principal place of business how see instructions on forms and 1010 what four percent normal tax on the amount of net income in excess of the personal exemption credit for dependents in excess of the personal exemption credit for dependents earned income credit and interest on obligations allie actions of tha united states and obligations of instrumentalities instrumental ties of the united states slates sui surtax tax on net income in excess of |