Mortgage Porting Explained: Can You Take Your Existing Deal to a New Property in 2026?

What Is Mortgage Porting — And Why Does It Matter Right Now?

With mortgage rates still elevated compared to the historic lows of 2020–2021, many homeowners are sitting on deals well below today’s market rates. If you’re thinking of moving home in 2026, porting your existing mortgage could save you thousands of pounds in interest — and avoid an early repayment charge (ERC) that might otherwise wipe out any saving.

But porting isn’t automatic, it isn’t always possible, and it comes with conditions that trip up even experienced homeowners. Here’s everything you need to know, laid out in plain English.

✅ Mortgage Porting Checklist: The Essentials at a Glance

Before diving into the detail, here’s a quick reference checklist to keep handy:

• Check whether your mortgage is portable (not all are)
• Confirm your current rate and any ERC that would apply if you switched
• Get a new affordability assessment from your lender
• Find out whether you need to borrow more — and at what rate
• Instruct a solicitor early, as timing is critical
• Confirm the new property meets your lender’s criteria
• Ask your lender for a porting Decision in Principle (DIP)

How Mortgage Porting Actually Works

Porting means transferring your existing mortgage — including its interest rate, term, and outstanding balance — from your current property to a new one. You’re not keeping the same mortgage account exactly, but you are keeping the same deal.

In practice, the process looks like this:

1. You apply to your lender to port your mortgage to the new property
2. The lender carries out a full affordability reassessment (just as if you were a new customer)
3. The lender also assesses the new property against its lending criteria
4. If approved, your existing rate is transferred — and any additional borrowing is arranged at a separate, current rate
5. Completion must typically happen within a set window (often 90–180 days, depending on the lender)

Key point: Porting is a lender privilege, not a legal right. Even if your mortgage documentation says it’s portable, your lender can decline your application.

When Porting Makes Financial Sense

The maths here can be compelling. Consider this example:

Sarah has a five-year fixed rate at 1.89%, taken out in 2022, with £180,000 outstanding and two years remaining. Today’s equivalent product is available at 4.65%. If she remortgaged instead of porting, she’d face an ERC of around £3,600 — plus the higher rate on the full balance.

By porting, Sarah keeps the 1.89% rate on her £180,000 and only pays today’s rate on any additional borrowing. That’s a significant monthly saving, potentially £400–£500 per month depending on the new loan size.

This is why porting has become increasingly attractive in 2025–2026, as buyers who locked in deals during the ultra-low rate era approach the end of their fixed terms.

When Porting Might Not Work — Common Obstacles

Despite its appeal, porting fails for several predictable reasons. Watch out for the following:

• Your income has changed. Self-employed borrowers, those who’ve recently changed jobs, or anyone whose income has fallen may fail the new affordability assessment — even if they’ve never missed a payment
• The new property doesn’t meet lending criteria. Lenders won’t accept unusual constructions (such as certain steel-framed or timber-framed homes), high-rise flats above a certain number of storeys, or properties with short leases
• The gap between sale and purchase. If there’s a delay between selling your current home and completing on the new one, you may technically repay your mortgage — triggering ERCs even if you planned to port
• Borrowing significantly more. If you need to borrow substantially more than your existing balance, the top-up portion will be at today’s rates, which could dilute the benefit
• Your lender has withdrawn the product type. Some lenders no longer offer the specific product you’re on, which can complicate porting even when it’s technically permitted

The Porting Process: Step by Step

1. Check Your Mortgage Agreement

Pull out your original mortgage offer document. Look for the word “portable” in the key features section. If you’re unsure, ring your lender directly or check your account portal.

2. Calculate Your ERC

Most fixed-rate mortgages charge an ERC of 1–5% of the outstanding balance if you leave early. On a £200,000 mortgage, that’s £2,000–£10,000. Compare this against the benefit of switching to a new deal at today’s rates.

3. Get a Porting DIP

Ask your lender for a Decision in Principle specifically for porting. This gives you a clearer picture of whether the new property and your current finances will be accepted before you commit to a purchase.

4. Appoint a Solicitor Early

Timing is everything. Your solicitor needs to coordinate the sale and purchase so that you don’t inadvertently repay your mortgage before the port is processed. Many porting failures come down to completion timing, not lender refusal.

5. Understand the Top-Up Terms

If you’re buying a more expensive property, ask your lender exactly what rate applies to the additional borrowing and for how long. In most cases, the top-up is a separate sub-account on a current product — which may have its own ERC.

Porting vs. Remortgaging: A Quick Comparison

Useful Resources

• MoneyHelper (moneyhelper.org.uk) offers a free mortgage affordability calculator and impartial guidance on porting and remortgaging
• The Financial Conduct Authority (FCA) regulates all UK mortgage lenders — if you believe you’ve been treated unfairly during a porting application, you can escalate to the Financial Ombudsman Service
• If your circumstances have changed significantly, consider speaking to a whole-of-market mortgage broker who can compare porting against switching lenders

Tip: Always get mortgage advice from an FCA-authorised adviser before making a decision. A broker’s fee is often offset many times over by the savings they identify.

Actionable Takeaways

• Don’t assume porting is automatic — apply formally and get it in writing
• Time your sale and purchase carefully to avoid accidentally triggering an ERC
• Run the numbers on any top-up borrowing before deciding porting beats a full remortgage
• Use a solicitor experienced in simultaneous transactions — this isn’t the place to cut costs
• Speak to a broker even if you plan to stay with your current lender; they can confirm you’re not missing a better deal elsewhere

This article is for informational purposes only and does not constitute regulated financial advice. Always seek advice from an FCA-authorised mortgage adviser before making decisions about your mortgage.