每半年付一次款 Pay Every Six Months

按半年付款 semi-annual installments

半年支付 SA semi-annual payment

年分期付款 annual payment

该年已付 P paid this year

预付年金 [会计] annuity in advance ; Annuity Due ; [会计] Prepaid annuity

即付年金 [劳经] Annuity due

迟付年金 annuity in arrears

一年以上的应付款项 Payables due after one year ; Accounts payable over a year