@Zhills I guess it would depend. If he has something like a coupon/payment book, I would think he could send in 12 consecutive payments.
My mortage company sent me monthly statements. I just paid a 15 year mortgage in 5 years and 6 months. I did it with extra principal, lol.
As soon as I would get the statement, I'd pay it and then the mortgage company would generate a new statement. I received the statement for the payment that would have been due 8-1-17 back in June 2017. That's when I ended it :-)
There are times when you must speak, not because you are going to change the opposing side, but because if you do not speak, they have changed you.