Change to mortgage P&I caused by extra payment

[Mike or Penny Novack]

On 12/23/2016 1:33 AM, JimR wrote:
> Thanks Peter.  The mortgage is actually variable 2.75%, but locked at
> that rate for the first 5 years.  After that, it can only change once
> each year.
>

There are simply too many possibilities for how an amortization table is 
created for us to expect agreement to the penny << where rounded off, 
how the end condition (the final payment) is to be treated,  etc. >>

When you make an additional principle pyement, in effect you have 
eliminated a payment in whole or in part << if you make the extra amount 
match the principle payment you have eliminated that payment and are 
skipping to the next >>  You might try having gnucash recalculated as if 
it were a new loan for the new amount and the N remaining payments. If 
the extra payment you made is NOT the exact amount of principle for the 
next N payments the "new loan" is the only way you can do it. But do NOT 
expect agreeing to the penny << I have written programs to calculate 
payments and produce amortization tables in my day -- including ones 
where it was possible to induce them to readjust to match what a bank 
had, but THAT perforce a manual operation of the sort "try adjusting up 
(or down) a penny >>

Michael D Novack