It seems that my mortgage company is holding partial payments I make in an account they call unapplied funds. The funds are not applied to the balance until the due date, not the date they were received. And if the partial payments do equal the total payment due by the due date, then nothing is applied until the total payment is received. 
It seems to me that holding the funds, since there is no prepayment penalty, gives the mortgage company more interest. And would defeat any attempt on my part to cut the interest by making early payments. 
