Moving Home With A Mortgage Explained

If you’re considering moving home but love your current mortgage deal, you might be able to take it with you. This process is called porting, and it can be a smart way to keep your interest rate and avoid hefty early repayment charges. But it’s not always straightforward, and there are some important details I know of as a mortgage broker that you should be aware of before you commit.

Porting is the transfer of your existing mortgage interest rate, outstanding balance and term from your current property to a new one. Instead of paying off your mortgage in full and taking out a brand-new deal, you port your current interest rate and terms subject to your lender’s approval and affordability checks.

Early Repayment Charges (ERC) and Refunds

When you repay a mortgage before the end of its product period, lenders usually charge an Early Repayment Charge. Porting can help you avoid these charges. In instances of porting the full balance or higher borrowing usually, the ERC you pay when redeeming the old mortgage is refunded once the new mortgage completes.

If you port but take a smaller loan than your current balance, you may still pay an ERC on the portion you’re repaying early, and that part is not usually refunded. For example: If you owe £200,000 but only need £150,000 on the new property, you may pay an ERC on the £50,000 you’re not carrying over.

Borrowing Additional Funds

If your new property costs more and you need to borrow beyond your existing balance, the extra amount will be on one of your lender’s current products. This means:

• The additional borrowing may have a different interest rate and term.
• You could end up with two sub-accounts on your mortgage, each with its own end date and rate.
• Consider how this may make remortgaging in the future challenging as having more than one part to your mortgage can lead to an ERC one part while the other is ERC free. This can keep you stuck with your existing lender if the ERC is costly.
• In most instances any additional borrowing would not be able to extend beyond your existing mortgage term

Timescales and Deadlines

Most lenders require that you complete the new mortgage within a set period after redeeming the old one, typically within 3 months of redemption. If you don’t complete within this window, you may lose the right to port your old product and could be left paying the ERC without a refund. Check with your lender as they may have a provision where you can extend the porting window beyond the initial 3 months. I have worked for lenders where there are significant wait times for appointments. Where possible using a mortgage broker rather than going direct to your lender can avoid this.

Key Takeaways

• Porting lets you transfer your current mortgage rate, balance, and term to a new property (subject to lender approval and affordability checks).
• Full balance ports often get ERC refunded, but downsizing may trigger non‑refundable ERC on the repaid portion.
• Any amount above your current balance goes on a new product with its own rate/term, which can complicate future remortgaging.
• Additional borrowing usually can’t extend beyond your existing mortgage term.
• Most lenders have a porting window of 3 months from redemption to keep porting benefits; missing the window can mean losing the deal and paying ERC. Check with your lender or mortgage broker to see if there is flexibility around this,