Porting a mortgage means transferring your existing deal to a new property when you move. Most fixed rate and tracker products are technically portable, meaning the lender allows you to apply for the same rate and terms on a different security. But there is an important distinction between the right to port and the guarantee that you will be approved.\n\nHow Porting Works — You apply to your current lender as if you were a new borrower, but requesting the same product terms. The lender reassesses your income, credit status, and the new property. If everything passes, your existing rate carries over to the new mortgage. If you need to borrow more than your current balance (because the new property costs more), the top-up usually comes at whatever rate your lender is currently offering.\n\nWhen Porting Makes Sense — Your current fixed rate is significantly lower than rates available today. You are mid-way through a fixed deal and the early repayment charge would be substantial. The lender is willing to let you port without additional arrangement fees.\n\nWhen It Does Not Make Sense — If current rates are lower than your existing deal, you are better off paying the early repayment charge and remortgaging onto a cheaper product. Run the numbers: a 2% ERC on a 200,000 mortgage is 4,000, but a 0.5% rate saving over 5 years saves 5,000. The maths often favours breaking the deal.\n\nThe Porting Trap — Your lender is not obliged to approve your port. If your circumstances have changed (new job, higher debts, different property type), they can decline. You are then stuck with a choice: pay the early repayment charge to remortgage elsewhere, or stay in your current home. Some lenders (notably Santander and HSBC) have been known to be stricter on porting applications than on new lending.\n\nTiming the Move — Most lenders give you a window (typically 30 to 90 days) to complete the port. If your sale completes but your purchase is delayed beyond this window, you may need to repay the existing mortgage and lose the rate. Talk to your lender early about their specific porting timeline requirements.