Before you sign your bank’s renewal letter, see what it costs versus switching: interest saved over the term, the balance difference at the end, and the keep-your-payment trick that shortens your mortgage for free.
A worked example: the letter vs the sheet
Say your $400,000 mortgage is renewing and the letter offers 4.64%. The best insured 5-year on my sheet is 4.24% as of August 24, 2026. Over a 25-year amortization that gap is about $88 a month, roughly $5,300 over the five-year term, for signing a different piece of paper. The calculator above runs your own balance and both rates, and switching at maturity has no penalty.
Frequently asked questions
Can I switch lenders at renewal without a penalty?
Yes. At maturity there is no penalty at all, and since January 2026 a straight switch no longer requires re-taking the stress test. The new lender typically covers legal and transfer costs to win your file.
Is my bank’s renewal letter negotiable?
It is a starting offer, not their best. Bring a competing quote and most lenders move. The gap between the letter and the market is usually thousands over a term, which is exactly what this calculator shows.
When should I start shopping my renewal?
About 120 days out. Rate holds protect you if rates rise, and you still take the better rate if they fall.