I had a chat with a supervisor level Chase mortgage person when I first started using evolve. Apparently there are different T&Cs on mortgages and Chase's system is kind of screwy on handling them.

Let's say my mortgage was $1K and I paid $1.8K the same day, it would get credited $1K P&I and $800 to P. If I did $2K same day, it would get credited as 2 payments. If I did $1.8K and then $200 the next, it would be 1 payment, and $800 and $200 towards principal.

Apparently as others have noted, if all your payments arrive on the same day and exceed your monthly payment, you'll get a payment + principal reduction on the difference.

What is not apparent is, that it's only to a point because some mortgages (like mine) allow pre-payments. Say you're going out of town, you can send in two payments and it will pay this month and the next. So that's why I got credited 2 payments worth instead of principal reduction on the middle scenario. My mortgage allows for up to 3 prepayments a month.

So anyways, took a long time to figure that out with the multitude of $100 and $200 payments I was doing on a much larger mortgage