Porting Your Mortgage: Can You Take Your Deal With You to a New Home?

If you’re moving home partway through a fixed-rate deal, porting - taking your existing mortgage rate with you to the new property - can avoid an early repayment charge and preserve a good rate, in much the same way switching before your current fix actually expires protects the rate for homeowners who are staying put. But it’s not automatic, and not always the best option. Here’s how it actually works.

What porting actually means

Porting allows you to transfer your existing mortgage deal - including its interest rate and remaining term - to a new property, rather than repaying it and starting a fresh deal elsewhere. This can be valuable if you’re currently on a competitive fixed rate that would otherwise attract an early repayment charge if you simply paid it off to move.

It’s not automatic - you still need to reapply

Porting isn’t a simple transfer; you need to reapply for the mortgage on the new property, going through a full affordability assessment as if it were a new application. Your lender assesses whether you still qualify based on your current income, outgoings, and credit history - not just whether you qualified originally. If your circumstances have changed for the worse since your original application, you may not be approved to port, even though you’re not asking to borrow more.

Borrowing more alongside a ported amount

If your new property costs more than your current one, you’ll typically need additional borrowing on top of the ported amount - and this additional portion is usually priced at your lender’s current rates, not the rate on your existing, ported deal. This means you can end up with two different rates on the same mortgage: your original rate on the ported portion, and a new rate on the additional borrowing.

When porting makes clear sense

• Your existing rate is meaningfully better than current market rates, making the early repayment charge you’d otherwise face genuinely worth avoiding.
• Your circumstances haven’t materially changed since your original application, so you’re confident of being approved for the new property.
• The new property’s value and loan amount are broadly similar to your current arrangement, minimising the complexity of blending an additional borrowing tranche at a different rate.

When it’s worth comparing against a fresh remortgage instead

• Current market rates are actually better than your existing deal - in this case, there’s no rate advantage to porting, and you may be better off simply remortgaging fresh with a new deal (see our dedicated remortgaging article).
• You need to borrow significantly more, where the blended rate across a ported portion and a new-rate portion might not compare favourably to a single fresh deal at current rates.
• Your existing lender’s product range doesn’t suit your new circumstances well - porting only gives you your existing lender’s options, not the whole market.

Checking your specific mortgage’s portability

Not all mortgage products are portable - check your original mortgage offer documents or ask your lender directly, ideally well before you start seriously house-hunting, so you know your options before making an offer on a new property that depends on a specific financing plan.

The bottom line

Porting can be a genuinely valuable way to preserve a good rate when moving home, but it requires a fresh affordability assessment and isn’t automatically better than a new deal - compare the blended cost of porting (existing rate plus any new-rate additional borrowing) against what’s available on the open market before assuming porting is the default right choice.