Hello, the handling fee for each installment of the bill = total installment amount × handling fee rate for each installment. The minimum handling fee for each installment is 5 yuan, 0.9% for the third installment, 0.75% for the sixth installment, 0.70% for 10 installment, 0.66% for 12 installment, 0.68% for 18 installment, 24.

Principal of each installment =8000/ 12

Handling fee for each period =8000*0.66%