<prompt> Human: So I made a payment on June 28th to what I believed was my car payment. I typically pay on the first but I got paid early thanks to a weekend payday and the way my bank works. The payment was due July 19th. Today, when I go to pay Augusts bill, it says I owe double plus a late fee. Like WHAT?!? Calling them and going on a crazy merry-go-round, I find out, eventually, that the principal only payment doesnt count towards the car payment. Interest is daily and making a principle only payment still leaves me on the hook. The 499.41 I pay a month is ALL interest?!? Like duh-FUQ?!? Paying off the car loan early doesnt lower the interest owed. At all. Well theyre gonna allocate the money I paid on the 28th to my July bill instead of principle only so itll make me break even. But how is this a thing? I feel cheated. This was never explained. This was never told to me ever even on paper. I had Wells Fargo dealer services once and when I did a principle only payment, it counted towards my bill every time. Why is this a thing? Someone please help me understand!!!  <response>: If you intentionally made a principal-only payment then you were telling Capital One that you didnt want the payment to be counted as your normal monthly payment. Thats how principal-only payments work. Interest accrues on a loan on a daily basis. Normal fixed-rate loans are amortized in such a way that the regular payment covers all of the accrued interest for that month plus some on the principal. Every month more of the payment goes to principal because the interest that accrues goes down. A principal-only payment takes money off the principal, which means less interest accrues. That means that when you make your next regularly scheduled payment more of that payment will be applied to the principal. That ultimately means that youll end up paying the loan off early and paying less in interest. Paying off the car loan early doesnt lower the interest owed. At all.Generally speaking, unless you took out a loan with a prepayment penalty, paying the loan off early does lower the interest owed. But you dont see the savings until the end of the loan. 