For many homeowners in 2025, the idea of moving house while holding a historically low fixed-rate mortgage can feel like a trap. You may have secured your current deal at 1.8% or 2.2% a few years ago, only to find today’s average rates hovering above 5%. The natural question becomes: Can I take my existing mortgage with me?
That’s where mortgage porting comes in. In principle, it allows you to transfer your current loan — including its rate and terms — to a new property when you move. It sounds straightforward, but the reality is more nuanced. Porting isn’t automatic approval, and whether it works depends on your lender’s criteria, timing, and how your finances have evolved since the original application.
In this guide, we’ll unpack how mortgage porting works in 2025, when it’s beneficial, what pitfalls to avoid, and why a remortgage or short-term finance can sometimes be the better route.
Mortgage porting means keeping your existing mortgage product and moving it from one property to another. You remain with the same lender and, ideally, continue on the same rate and terms. However, even though you’re not switching banks, you’ll still go through a full reapplication process.
Your lender will reassess affordability, check your income and credit, and revalue the new property. This means a borrower who once qualified easily could now face challenges if their income has changed, their debt has increased, or the new property type doesn’t meet policy criteria.
In short, porting is a new loan under old terms — not an entitlement.
For context on how underwriting standards have evolved, see How Mortgage Underwriting Has Changed in 2025.
Porting is particularly relevant in 2025 because of the interest rate environment. Many borrowers are sitting on mortgage deals fixed during the ultra-low period of 2020–2022. Moving home now could mean losing that advantageous rate and replacing it with a much higher one.
Porting helps preserve these older, cheaper rates. It also allows borrowers to avoid early repayment charges (ERCs) that can apply when redeeming a fixed-rate mortgage early — charges that often range from 3% to 5% of the balance.
However, lenders are cautious. A port request must still fit within affordability metrics and current risk appetite. Even existing customers can be declined if they no longer meet updated lending criteria.
Understanding this dynamic — between legacy affordability and modern underwriting — is essential before relying on porting as part of a moving strategy.
Imagine you currently have a £250,000 mortgage with a five-year fix at 2.19%, due to end in 2027. You want to move to a new home worth £400,000. If your lender approves the port, there are several potential outcomes.
If you need to borrow more, your lender may allow a top-up loan to cover the additional borrowing, but it will be issued at current market rates. You will then have two parts to your mortgage: the original balance at 2.19% and the top-up at, for example, 5.2%. These two sub-accounts may have different end dates, repayment methods, or terms.
If you plan to borrow less, you can port only part of the loan and repay the rest, though a partial ERC may apply on the repaid amount.
Finally, if you’re moving before selling your existing property, a short-term bridging facility may be required to complete the purchase before redemption. In such cases, it’s crucial to plan for both the porting process and the bridging exit carefully. For further reading, see How Fast Can Bridging Finance Be Arranged?.
Porting tends to work best for borrowers whose circumstances have remained broadly stable since their last mortgage application. If your income, credit status, and outgoings are similar, the lender’s risk profile remains consistent, making approval smoother.
The process also benefits those moving within a similar price bracket, especially if completion of both sale and purchase happens simultaneously. Most lenders allow a short grace period — typically 30 to 90 days — between the sale of the old property and the purchase of the new one. Beyond that, the offer may lapse or require a bridging arrangement.
Porting can also be advantageous if your current product is particularly competitive or includes valuable flexibility, such as overpayment allowances or offset features. Losing those benefits in a full remortgage might not be worth a small interest saving elsewhere.
For further context, see Everything You Need to Know About Offset Mortgages.
Despite the appeal, many porting applications fall through. The most common issues include:
1. Changes in income or employment – If you’ve switched jobs, gone self-employed, or experienced reduced hours, your affordability assessment may differ significantly from when you first applied. Borrowers in this position may find lenders unwilling to match previous borrowing levels. See Mortgages for Self-Employed Borrowers in 2025: What You Need to Know for a detailed explanation of lender assessment trends.
2. Property type issues – Porting can be rejected if the new home is considered higher risk — such as ex-local authority, high-rise, or non-standard construction. Each lender’s property criteria are unique, and valuations remain key to approval.
3. Inconsistent timing – If your sale completes before your purchase, the lender may not hold the old rate open long enough to allow completion. The same applies if your onward purchase falls through and the completion window expires.
4. Top-up loan complexity – Managing two separate mortgage parts can complicate future remortgages, as both sub-accounts may have different expiry dates. Coordinating these in the future often requires bespoke lender negotiation or refinance.
5. Misunderstanding ERCs and fees – Borrowers sometimes assume porting removes all costs. In reality, valuations, legal fees, and partial ERCs can still apply.
Being proactive with timing, paperwork, and expectations prevents most of these pitfalls.
While porting helps preserve a low rate, it isn’t always the best financial move. If your fixed period is nearly over, or if you need additional borrowing on better terms, it may be more efficient to remortgage.
A full remortgage can allow you to extend the term, consolidate debt, release equity, or switch lenders for a more flexible product. Some borrowers also use remortgaging to restructure their loan between personal and limited company ownership, particularly where they own rental property.
You can explore these options further in Limited Company Mortgages Explained and Is It Time to Remortgage? Key Signs to Watch in 2025.
Ultimately, porting works best as a cost-preservation tool, while remortgaging remains the strategic restructuring tool.
If you’re considering a move, plan your porting process months in advance. Ask your lender (or broker) to confirm whether your product is portable and whether your circumstances are still aligned with their affordability model.
Check your mortgage offer documents to see:
You should also assess whether your new property might affect eligibility — particularly if it involves commercial use, mixed tenure, or complex leasehold arrangements. For more on how these factors shape finance availability, see How to Finance Property with Commercial Tenants Above or Below in 2025.
In 2025, porting remains a useful mechanism for borrowers with valuable fixed rates — but it’s not a guaranteed solution. It relies on lender cooperation, consistent affordability, and tight transaction timing. For those with changing income or unconventional property types, a tailored refinance or bridge-to-term structure may be safer.
A specialist broker with access to both mainstream and private lenders can model both routes — comparing total costs, timings, and flexibility — to determine whether porting truly preserves value or simply delays an inevitable refinance.
Q1. Can every mortgage be ported?
No. Most fixed and tracker mortgages are portable, but lenders can decline a port request if your circumstances or the new property fall outside policy criteria.
Q2. Will I need to go through full underwriting again?
Yes. Porting triggers a new affordability assessment, credit check, and property valuation — similar to a new mortgage application.
Q3. What if my new home is cheaper than my current one?
You can port a smaller balance but may pay an early repayment charge on any amount repaid.
Q4. Can I port if I haven’t sold my current property yet?
Yes, but only if the lender allows temporary bridging. The sale must usually complete within a set timeframe, often 60–90 days.
Q5. Is porting always cheaper than remortgaging?
Not always. While it can preserve a low rate, fees, top-up interest, or partial ERCs can make a new mortgage more cost-effective over the full term.
If you’re planning to sell and buy in 2025, understanding whether you can — or should — port your mortgage could make a significant financial difference.
At Willow Private Finance, we assess every angle: your current product, lender criteria, future affordability, and how the move fits into your wider financial strategy. Our advisors specialise in helping clients protect low legacy rates while still securing the flexibility they need for their next property.
We’ll compare the true cost of porting versus remortgaging, factor in all fees and timing risks, and help you plan a seamless transition that avoids unnecessary charges or delays.
Book a confidential, no-obligation discussion with one of our mortgage specialists today.
About the Author
Wesley Ranger, Director of Willow Private Finance, has spent over two decades advising clients on complex and high-value property finance. His experience spans residential, buy-to-let, and private bank lending, with particular expertise in bespoke funding structures for high-net-worth and international clients. Wesley regularly contributes to Willow’s insight series on property finance trends and lending strategy.
Important Notice
This article is provided for general information purposes only and should not be relied upon as personal financial or mortgage advice. Mortgage porting, remortgaging, or any form of property finance decision should always be assessed against your individual circumstances, income stability, credit profile, and long-term objectives.
The examples provided are for illustration only and may not reflect your lender’s specific criteria or current market conditions. Lending policies, affordability models, and eligibility rules can change without notice. Borrowers should also be aware that not all mortgage products are portable, and approval of a ported mortgage is not guaranteed, even where the existing account remains in good standing.
You should seek regulated, independent mortgage advice before making any commitment to port, redeem, or restructure an existing mortgage. Your home may be repossessed if you do not keep up repayments on your mortgage.
