Hong Kong Mortgage Prepayment Calculator | Penalty & Partial Prepay

A mortgage normally charges interest on the declining principal, so an earlier principal reduction can lower future interest. This is different from a personal loan that uses the Rule of 78; do not reuse a personal-loan settlement formula for a mortgage.

After a partial prepayment, a lender may keep the instalment and shorten the term, or keep the remaining term and lower the instalment. The first usually saves more total interest; the second prioritises monthly cash flow. Available choices, minimum amounts, notice and payment dates depend on the facility letter and lender process.

Published bank documents show that there is no single Hong Kong penalty formula. A lender may quote a percentage of the prepaid amount, months of interest, a minimum charge, an administration fee and a cashback clawback. This calculator separates those items and prioritises a written quote for a stated date over any shortcut scenario.

The decision also changes liquidity. The page subtracts the prepayment and entered costs from liquid cash, then compares the remainder with the user's essential-spending target. Money paid into the mortgage may not be available again on the same terms when an emergency occurs.

The model holds the entered rate constant, estimates the current instalment from principal, rate and term, and excludes the return that retained cash might earn. A prepayment of at least 90% can trigger full-redemption rather than ordinary partial-prepayment terms. The lender's settlement quote, revised schedule and facility letter remain authoritative.