Mortgages Clarified (?)

Here is a typical amortization schedule:

Monthly	Remaining	Principal	Interest
Payment	Owed	Paid	Paid
$0	$100,000	$0	$0
$599	$99,900	$99	$500
$599	$99,800	$100	$500
$599	$99,700	$100	$499
$599	$99,599	$101	$498
$599	$99,497	$101	$498
$599	$99,395	$102	$497
$599	$99,293	$102	$497
$599	$99,190	$103	$496
$599	$99,086	$103	$496
$599	$98,982	$104	$495
$599	$98,877	$104	$495
$599	$98,772	$105	$494

Notice that you could double up payment 1 and Payment 2 by simply adding $100 to payment 1. Adding another $101 to payment 2 takes care of payments 3 and 4.
Adding $102 to payment 3 takes care of payments 5 and 6.
and so on. In fact, you could simply add $105 to the payment for six months to knock six payments off the end of the mortgage. You invest $1,260 to save $3,594.

You can add principal at any time, without making any special arrangements with the mortgage company.