What does porting a mortgage mean?
Porting is the process of moving your existing mortgage — including the current interest rate, remaining term, and outstanding balance — from your current property to a new one. It’s not a legal right; it’s a feature offered by many (but not all) lenders.
When you port, you’re essentially applying for the same mortgage on a different property. The lender will still reassess your affordability and value the new property, so approval isn’t guaranteed.
Can you port any mortgage?
Not all mortgages are portable. Whether yours can be ported depends on your lender and the specific product terms. Check your mortgage offer document or contact your lender directly.
Even where porting is available, the lender may impose conditions. They’ll want the new property to meet their lending criteria, and you’ll need to pass a fresh affordability assessment. If your circumstances have changed (lower income, new debts, credit issues), the port could be declined.
Don’t assume your mortgage is portable
Some products specifically exclude porting, and some lender types (like certain building societies or specialist lenders) don’t offer it at all. Always confirm with your lender before making plans based on porting.
Porting to a more expensive property
If your new property costs more than your current one, you’ll need to borrow extra on top of your ported mortgage. This additional borrowing is usually arranged as a separate loan (sometimes called a “top-up”) which may be at a different interest rate.
For example, if you’re porting a £200,000 mortgage at 3.5% and need to borrow an extra £80,000, the top-up might be at the lender’s current rate of 4.5%. You’d effectively have two loans running in parallel on the same property.
The lender will assess your affordability for the total borrowing (£280,000 in this case). If the numbers don’t work, they may decline the additional borrowing even if they’re happy to port the original amount.
Porting to a cheaper property
If you’re downsizing or moving somewhere less expensive, you’ll need to repay part of your mortgage. This partial repayment may trigger an early repayment charge on the amount being repaid, even though you’re porting the rest.
For example, if you’re porting a £250,000 mortgage but only need £180,000 on the new property, you’d repay £70,000. If your ERC is 3%, that’s a charge of £2,100 on the repaid portion. The remaining £180,000 continues at your existing rate with no charge.
What are the pros and cons of porting?
Porting can be the right choice in some situations and the wrong one in others. Here’s how to weigh it up.
| Advantages of porting | Disadvantages of porting |
|---|---|
| Avoid paying ERCs on your full mortgage balance | You’re limited to what your current lender will offer |
| Keep a rate that may be lower than what’s currently available | Top-up borrowing may be at a higher rate |
| Maintain your existing relationship with the lender | You still need to pass a fresh affordability check |
| No legal fees or valuation costs on the ported portion (with some lenders) | A better overall deal might be available elsewhere (even after paying the ERC) |
Porting vs remortgaging: which is better?
The answer depends on the numbers. Sometimes paying an ERC and switching to a cheaper rate across the whole balance works out better than porting at the old rate and paying more on the top-up.
A broker can calculate both scenarios and show you the total cost over the remaining term. This includes ERCs, arrangement fees, legal costs, and the difference in monthly payments. Often the comparison is closer than people expect.
Ask your broker to run a “port vs remortgage” comparison showing the total cost of each option over 2, 5, and 10 years. The right choice becomes clear when you see the full picture.
How to check if your mortgage is portable
Start by checking your original mortgage offer document — it should state whether porting is allowed under the product terms. If you can’t find it, call your lender’s customer service line and ask directly.
Your broker can also check this for you and, if porting is available, assess whether it’s actually the best option compared to the alternatives on the open market.
Get expert advice on porting your mortgage
At Clearview Mortgage Solutions, we’ll review your current deal, check whether porting is available, and compare it against the best remortgage options on the market. We’ll show you the numbers for both paths so you can make an informed decision.
Contact us for a free, no-obligation porting review.