The Internal Revenue Service publishes detailed instructions for federal Form 1040A on its website, including the restrictions on who can use Form 1040A and line by line directions for completing the form. Only filers with taxable incomes of $100,000 or less who do not itemize deductions may use Form 1040A, according to the IRS.
To complete Form 1040A, filers input their income from all sources, then allowable adjustments to income, according to the IRS. Taxpayers subtract their standard deductions and exemptions from income, and determine their taxable income and tax using provided tables and worksheets. Allowable credits reduce the amount of tax if claimed. Filers calculate their tax refund or the amount they owe the government on Form 1040A lines 47 and 50, as of 2015.
There are limits on the types of income, adjustments and credits that can be reported and claimed on Form 1040A, states the IRS. For example, income derived from self-employment cannot be reported using Form 1040A. Income from wages, capital gains, interest, scholarships, retirement accounts or Social Security can be reported on Form 1040A. The only allowable adjustments to income on Form 1040A are educator expenses, student loans, tuition and fees deductions, and IRA deductions. Form 1040A allows filers to claim eight specific tax credits, including the child tax credit and Earned Income Tax Credit.