When does refinancing or a balance transfer break even?

Why the lower rate is only the first part of the comparison

Replacing an existing mortgage or home loan usually creates a new borrowing structure. The rate may change, the repayment term may change, and there may be arrangement, valuation, legal, registration, discharge, transfer or administration costs. Some offers include cashback or credits. The economic result depends on the combination, not one headline number.

That is why Carrowmont shows three repayment figures: The current modeled payment, the payment under the new rate using the same remaining term, and the payment under the proposed new term. The middle figure isolates the rate effect.

Why financed fees are not “free”

Adding a switching fee to the new mortgage can reduce the cash needed at completion, but it increases the amount borrowed. The fee remains part of the refinance economics and the larger principal can produce additional interest over time. This is why a “no upfront cash” structure is not the same as “no cost.”

What does durable break-even mean?

A simple break-even calculation often divides costs by monthly payment savings. That can be useful as a rough shortcut, but it can miss term effects and changes in the interest path. Carrowmont instead compares cumulative modeled borrowing cost over time.

The refinance path reaches durable economic break-even at the earliest point where its modeled advantage becomes non-negative and does not fall negative again through the full modeled horizon. If the refinance looks favorable temporarily but a longer term later adds enough interest to reverse the advantage, the tool reports No durable break-even rather than promoting the temporary crossing.

Why your expected holding period matters

If you expect to sell, refinance again or switch products in a few years, lifetime savings alone may not answer the practical question. You may not have enough time to recover the costs. The holding-period result asks: If both paths were settled at that point, which path has the lower modeled borrowing cost after the entered switching costs and incentive?

How a longer term can hide inside a lower payment

Extending the term spreads repayment over more periods. That can reduce the periodic payment even when it increases the total interest paid. A fair refinance comparison therefore keeps the same-term rate-only payment visible beside the actual proposed-term payment. This prevents the lower payment from being attributed entirely to the rate.

What about a shorter refinance term?

A shorter term can raise the periodic payment while reducing lifetime interest. That does not automatically make the refinance unfavorable. Payment affordability and borrowing-cost efficiency are separate questions, and MDC1B deliberately does not perform a lender affordability or eligibility test.

When might there be no durable break-even?

Examples include switching costs that are too large for the interest reduction to recover, a higher rate without enough offsetting term benefit or incentive, or a proposed term that accumulates more interest over the long run. In those cases the correct output is a clear no-break-even status—not an invented month.

What Carrowmont does not model automatically

The calculator does not fetch lender products or live rates, rank lenders, determine qualification, calculate a country-specific penalty, normalize APR/APRC/comparison rates, forecast variable rates, model tax deductions, or estimate property value and sale costs. Enter actual charges from your documents and use local professional or lender guidance where rules matter.

Frequently asked questions