Porting vs Remortgaging in the UK: Keeping Your Deal When You Move House

When you move house in the UK, you can often “port” your existing mortgage deal to your new property, avoiding early repayment charges while keeping your current interest rate. However, porting is not always the best choice: if market rates have fallen, remortgaging to a new deal may save you more money even after paying the early repayment charge. The right option depends on your current rate, remaining deal period, the early repayment charge, and whether you need to borrow more or less.

Understanding Your Options When You Move House

If you move home during your mortgage’s fixed-rate or tracker deal period, you face a choice. You can port your existing mortgage to the new property, keeping the same rate and avoiding the early repayment charge (ERC). Alternatively, you can remortgage to a new deal with any lender, which may offer a better rate but typically triggers an ERC on your current mortgage.

According to MoneyHelper, most UK mortgage products include portability clauses, but the lender must approve the new property and reassess your affordability. Porting is not automatic, and you may not qualify if your circumstances or the property value have changed significantly.

Comparison: Porting vs Remortgaging

Feature	Porting Your Mortgage	Remortgaging to a New Deal
Early repayment charge	Usually avoided (if ported within the allowed window)	Typically payable (often 1% to 5% of outstanding balance)
Interest rate	Keeps your current deal rate	Access to current market rates (may be lower or higher)
Lender choice	Must stay with your current lender	Can switch to any lender
Additional borrowing	Often possible, but new funds may be at a different rate	New total loan at one rate
Affordability check	Required (you must re-qualify)	Required (standard remortgage assessment)
Timeline	Must complete within lender’s window (often 90 to 180 days)	More flexible timing
Application complexity	Single application with existing lender	New lender, full application, conveyancing

Porting Your Mortgage: How It Works

Porting allows you to transfer your existing mortgage deal to a new property. You apply to your current lender, who assesses the new property’s valuation and your affordability using current lending criteria. If approved, your mortgage balance, interest rate, and remaining deal period move to the new home.

Pros of Porting

No early repayment charge: You avoid the ERC that would apply if you repaid the mortgage early, which can be substantial (for example, 3% of a £200,000 mortgage is £6,000).
Rate protection: If you locked in a low fixed rate and rates have since risen, porting preserves your advantage.
Simpler process: You stay with one lender, which can streamline paperwork and reduce application fees.

Cons of Porting

May miss better deals: If market rates have fallen below your current rate, you pay more interest than necessary.
Limited flexibility: You must complete the move within the lender’s porting window (typically 90 to 180 days). Missing the deadline means paying the ERC anyway.
Not guaranteed: The lender can decline to port if the new property fails valuation, if your income has dropped, or if your credit situation has changed.
Borrowing mismatch: If you need to borrow significantly more, the additional funds are usually at a different (often higher) rate. If you borrow less, you may still pay an ERC on the reduction.

Remortgaging to a New Deal: How It Works

Remortgaging involves paying off your current mortgage (triggering the ERC if you are still in the deal period) and taking out a new mortgage with any lender at current market rates. You go through a full application, including affordability assessment, credit check, property valuation, and conveyancing.

Pros of Remortgaging

Access to the best current rates: You can shop across all lenders for the lowest rate and most suitable product, as discussed in foundational texts such as Principles of Finance when evaluating loan refinancing decisions.
No porting restrictions: You are not limited by your current lender’s criteria or timelines.
Flexible borrowing: The new mortgage amount can be tailored to the new property value and your needs without complex tiered rates.
Potential savings: Even after paying the ERC, switching to a significantly lower rate can save money over the remaining term.

Cons of Remortgaging

Early repayment charge: You pay the ERC, which can be thousands of pounds depending on your outstanding balance and how much of the deal period remains.
Application fees and costs: New arrangement fees, valuation fees, legal fees, and potentially higher interest if rates have risen.
Longer process: A full remortgage takes longer and involves more paperwork than porting.

Which Option Is Right for You?

Port Your Mortgage If:

Your current rate is lower than current market rates and you are early in your fixed or tracker deal period.
The early repayment charge is high (for example, 5% or more of the outstanding balance).
You can complete the move within the lender’s porting window and the new property meets their criteria.
You do not need to borrow significantly more or less (small adjustments are usually manageable).

Remortgage to a New Deal If:

Current market rates are lower than your existing rate by enough to offset the ERC and new fees.
You are near the end of your deal period and the ERC is small or zero.
Your current lender cannot or will not approve the port due to property type, location, or affordability concerns.
You want to release equity or significantly change the loan amount, and porting would create a complex split-rate mortgage.
You need more time or flexibility and cannot meet the porting deadline.

Key Considerations and Next Steps

Before deciding, calculate the total cost of each option. For porting, add up your remaining deal period payments at the current rate. For remortgaging, add the ERC, new fees, and total payments at the new rate over the same period. Which? recommends requesting a personalised illustration from both your current lender (for porting) and at least two other lenders (for remortgaging) to compare real figures.

Check your current mortgage terms for portability clauses and ERC schedules. Contact your lender as soon as you plan to move to confirm porting eligibility and timelines. If remortgaging appears cheaper, speak to a whole-of-market mortgage broker who can identify the best deals across all lenders.

Remember that rates, fees, and lending criteria change frequently. Always verify current terms with an FCA-authorised mortgage adviser before deciding, and factor in any changes to your income, credit file, or deposit since you took out your current mortgage.

Conclusion

Porting and remortgaging each suit different circumstances. Porting protects you from early repayment charges and preserves a good rate if the market has moved against you, but remortgaging can unlock better deals if rates have fallen or your situation has changed. Run the numbers for both options, account for all fees and charges, and consult an FCA-authorised mortgage adviser to ensure the choice fits your financial situation and timeline.

Financial Disclaimer: This article provides general educational information about UK mortgage options and is not regulated mortgage advice. Refisage is not authorised by the Financial Conduct Authority (FCA). Mortgage products, rates, eligibility criteria, early repayment charges, and porting terms vary by lender and by your individual circumstances. Your home may be repossessed if you do not keep up repayments on your mortgage. Speak to an FCA-authorised mortgage adviser for personalised guidance before making any mortgage decisions.