<prompt> Human: I have been paying down my auto loan with multiple pays per month. My current loan seats at 10655, 20. My monthly payment is 431. I made like 4 payments this month. It was originally at 13026. The due keeps on getting push back now. Says I dont owe anything until Oct 13 2015. I dont trust that though.Even though I dont owe until then, do I continue to gain interest charges? Im going to continue paying down every month and chance that I get. There is no prepay penalty. Reason Im asking is because my current status says, 10 day payoff is like 100, and 20 day payoff is 200 more. Does this take effect on the actual due date they have on record? Or is this 10-20 days from my last payment?  <response>: Talk to the servicing agent and tell them you want the excess applied to the principal, not held for future months.The way you described things happening equates to them not only getting more interest out of you by not reducing the principal faster, but they also get to EARN interest on the extra you paid until they actually decide to apply it. It is a double dipping tactic sometimes used by scummier lenders. 