Should you switch or stay?
Whether to stay with your lender on a product transfer or switch to a new lender comes down to total cost, not the headline rate. Staying is fast and usually fee-free but limited to one lender's rates; switching opens the whole market but adds fees and, if you leave a deal early, an early repayment charge. This free tool compares the monthly payment and the total cost over your chosen period for both, so you can decide on the numbers.
Compare the two options
Free. No email needed. Runs in your browser, stores nothing.
Stay
Monthly:
Total over period:
Switch
Monthly:
Total over period:
Simplified illustration. It assumes each rate runs for the whole comparison period and ignores changes after that, overpayments and rate moves. Not advice. A regulated broker can confirm the real figures for your case.
How to read the result
The monthly figure shows what each option costs each month at that rate over your remaining term. The total over the period adds those payments up across your comparison window and adds the fees, plus any early repayment charge for switching. A lower switch rate can still lose once fees and an ERC are included, which is exactly the trap this tool is built to expose. If the totals are close, the easier, more certain option often wins.
Common questions
How does this tool work?
You enter your balance, the years left on your mortgage, and the rate and costs for each option (staying on a product transfer, or switching to a new lender). It works out the monthly payment for each and the total cost over the comparison period you choose, including fees and any early repayment charge. It runs entirely in your browser and stores nothing.
Is this regulated mortgage advice?
No. It is an information tool to help you see the numbers. It does not recommend a product. For a recommendation suited to your circumstances, we introduce you to a regulated mortgage broker who can advise you.
What does it leave out?
It is a simplified comparison. It assumes each rate runs for the whole comparison period, and it does not model what happens after the deal ends, overpayments, or changes in the base rate or swap rates. Treat the result as a guide, not a precise quote.
What is an early repayment charge?
An ERC is a fee for leaving your current deal before it ends, usually a percentage of the balance. If your deal is already ending you normally pay no ERC, so leave that field at zero. See early repayment charges for detail.
Background reading: remortgage vs product transfer and early repayment charges.
Founder, MortgageExplained, MortgageExplained
Adam spent nearly a decade as a mortgage adviser at Just Mortgages, with further experience in commercial finance. He is CeMAP and CF qualified. He built MortgageExplained to do one thing well: explain mortgages in plain English, then introduce you to a regulated broker when you are ready. Every page is written and reviewed by Adam.
Last reviewed: 29 June 2026