[yamtaddle]

> In the US, I have never read about not being able to pay or a penalty for paying the entire mortgage at anytime.

My parents (we're all American) were always very careful to check that early repayment didn't come with a penalty, on mortgages and all other loans, so I assume it used to be a thing. I've always asked (following their example) and not once had the answer be "yes, there's an early-repayment fee" so maybe it's a whole lot less common than it used to be.