Compare your current mortgage deal with a new rate before you switch. This calculator estimates your current monthly payment, a new remortgage payment, fee-adjusted savings and how long it could take to break even on lender costs.
Use the remaining balance on your current mortgage, not the property value. Fees and ERC are treated as upfront switching costs. If your new lender adds fees to the loan, your real payment could be slightly higher.
A deal with a cheaper headline rate can still lose out if the fee is large, the fixed period is short or you plan to move again before the savings catch up.
Arrangement fees, valuation charges, legal fees and early repayment charges all matter. Cashback can offset them, but only if it is genuinely paid to you rather than used against another fee.
If you are likely to sell, overpay heavily or refinance again before break-even, a no-fee product can sometimes beat a lower-rate product with chunky charges.