If the current balance is $13,000, how long will it take for the account to be paid off? 

One of your customers is delinquent on his accounts payable balance

If the current balance is $13,000 and the repayment schedule is $500 per month with 1.40 percent interest per month on the overdue balance, then it will take 26 months for the account to be paid off. This can be calculated using a present value formula where PV = PMT/r where r = (1+i)^n -1 and i = interest rate (1.40%), n= number of monthly payments (26), and PMT= repayment amount ($500).