TaxSlayer’s Simply Free is available to single or married individuals filing jointly, with no dependents, valid SSN or ITIN, under age 65, not blind, claiming the standard deduction, and having a taxable income of $100,000 or less from specific sources; they can also claim the American Opportunity Tax Credit, Lifetime Learning Credit, and/or the student loan interest deduction.

https://www.taxslayer.com/policies/simply-free/ 

Individuals with income from sources such as Social Security benefits, self-employment, rental income, stock sales, clergy income, U.S. Virgin Islands business income, gambling winnings, unearned taxable income for a child under age 18, foreign earned income, distributions from a pension, annuity, or IRA, or those claiming credits and deductions like the Earned Income Tax Credit, Child Tax Credit, Mortgage interest deduction, etc., are not eligible for TaxSlayer’s Simply Free. This is where BarBiz can come in to help.