分期付款

pay in 12 installments : 分12期付款
pay in monthly installments : 按月分期付款
pay in 12 monthly installments : 12個月分期付款


http://www.utexas.edu/policies/hoppm/pm3117.html
"...
It is possible for the University to pay 9-month faculty salaries in 12 equal monthly payments to those full-time faculty members
...
"


big5.chinalawinfo.com/eng.chinalawinfo.com/law/display.asp
"... the ratio of initial installment of payment and interest rate shall be raised as the number of homes increases ..."