Amortization
Amortization is the repayment of a loan through regular payments that cover the interest accrued and apply the remainder to principal. A fully amortising loan reaches a zero balance on the last scheduled payment, with nothing left over.
The mechanics#
Each period the lender calculates interest on the outstanding balance. The payment covers that interest first. Whatever remains reduces the principal.
Because the balance is now smaller, next period's interest charge is smaller — so more of the identical payment reaches principal. Repeat three hundred and sixty times and the balance reaches zero exactly.
The payment never changes on a fixed-rate loan. The composition of it changes every single month.
Why the early years feel slow#
On a thirty-year mortgage the balance is at its maximum on day one, so the interest charge is at its maximum too. The principal reduction in the first year is small in absolute terms and the effect compounds slowly.
People frequently look at a statement after two or three years of payments, discover the balance has barely moved, and conclude something is wrong. Nothing is wrong. That is what the arithmetic produces.
Fully amortising and not#
Not every loan amortises to zero.
An interest-only loan pays no principal at all during its interest-only period; the balance at the end is what it was at the start.
A balloon structure calculates payments on a long amortisation — thirty years is common — but matures far sooner, leaving a substantial balance due in one lump. The monthly payment is comfortable and the maturity date is not.
Both are legitimate structures with real uses. Both punish a borrower who assumed the loan would take care of itself.
Where it matters for distressed property#
An amortisation schedule tells you the balance on any given date, which is what determines whether there is equity in a property at the moment it enters distress. Two identical houses with identical mortgages taken out eight years apart are entirely different propositions.
Recasting#
There is a third option most borrowers never hear about.
A lump-sum payment to principal shortens the loan while leaving the monthly payment unchanged. A recast takes that same lump sum and re-amortises the remaining balance over the remaining term, which lowers the monthly payment instead.
Same money, opposite effect. Shortening the term saves more interest; recasting reduces the monthly obligation. For a household whose problem is cash flow rather than total cost, the recast is the one that helps, and servicers generally charge only a modest fee for it.
Not every loan permits it, and it is rarely offered unprompted. It has to be asked for by name.