From a tax perspective, it ultimately doesn’t matter whether they file as singles or married jointly. According to my calculations, their taxes payed married jointly ($18,400) is actually the exact same as the sum of their individual taxable income ($9,200). Therefore, the amount of taxes they have to pay will also be the same. ($955 for each)
Single Married
Taxable Income= $9,200 Taxable Income= $18,400
$8,500*.10= $850 $17,000*.10= $1,700
$9,200-$8,500= 700*.15= $105 $18,400-$17,000= $1,400*.15=$210
$105 + $850 $1,700+ $210
Taxes to pay: $955 Taxes to pay: $1,910