Completed our tax return on Turbo Tax. For our return, the turbo tax calculation for taxable income matched the IRS tax table tax for the same taxable income. However, in helping out a friend, the turbo tax calculation for $12,539 taxable income gave a tax calculation of $623 (effective tax rate of 2.34%) whereas, the IRS tax tables in the 1040 Instructions booklet for single, $12,539 taxable income shows a total tax of $1,306. Why such a difference?
