When Is It Actually Worth Switching Your Mortgage?

Start with the rate your own bank will give you

Before comparing other lenders, ask your current lender for its best rate for your loan-to-value band — an internal rate switch costs nothing and needs no solicitor. That rate, not your current rate, is the true benchmark. Plenty of people switch banks to reach a rate their own bank would have matched with a phone call.

The three numbers that decide it

First, the monthly saving at the new rate over the same remaining term — not a longer term, which manufactures a fake saving by adding years of interest. Second, net switching cost: legal fees plus valuation plus any break fee, minus cashback. Third, your horizon: how many months you will realistically hold this mortgage before selling, trading up or switching again.

If monthly saving multiplied by horizon comfortably exceeds net cost, the switch works. Our savings calculator runs the break-even month for you on your own figures, on your own device.

Where the arithmetic goes wrong

Common distortions: extending the term to flatter the monthly figure; ignoring a fixed-rate break fee (get the written quotation — it may be smaller than feared, or zero); treating cashback as free money rather than netting it against costs and checking clawback conditions; and forgetting that a rate advertised for new business may require a fresh valuation putting you in a worse loan-to-value band than you assumed.

The costs are the small number

On a standard remortgage, the entire legal-and-valuation cost is usually a few weeks' worth of the interest saving on a meaningful rate gap — and frequently covered entirely by cashback. The real cost of switching is attention: paperwork, insurance, signatures. The real cost of not switching is paid monthly, forever, in interest.