If you move house while still tied into a fixed or discounted mortgage deal, you might assume you'll have to pay an early repayment charge to leave it. In many cases, though, you can instead "port" the mortgage — transferring your existing rate and terms to a new property, rather than starting a fresh deal from scratch. It sounds simple, but porting comes with more conditions than most people expect.
What porting actually means
Porting isn't a physical transfer of a loan — the old mortgage is technically repaid and a new one is set up on the new property, but the lender allows you to keep the same interest rate and terms, and avoid the early repayment charge that would otherwise apply for leaving the deal early. It's essentially a lender-specific benefit built into many (though not all) fixed and tracker mortgage products.
The conditions that catch people out
- Not all mortgages are portable. Check your original mortgage offer or ask your lender — porting isn't guaranteed on every product
- You still have to reapply. Porting requires a fresh affordability and credit assessment as if it were a new mortgage application — your circumstances, income, or the property's suitability may have changed since you first took out the loan, and the lender can refuse to port if you no longer meet their criteria
- Timing matters. Most lenders require the new purchase to complete within a set window (commonly around 90 days) of selling the old property, or the porting arrangement may lapse
- The new property must meet the lender's criteria just as any new mortgage application would — its type, condition, and value all matter
What happens if you need to borrow more
It's common to need a larger mortgage when moving to a more expensive property. In this case, the ported portion keeps its original rate and terms, but the additional amount you need to borrow is typically arranged as a separate new sub-account, at whatever rate the lender is currently offering for new lending — not the rate on your original deal. This means your overall mortgage can end up as a blend of two rates: your old, ported rate on part of the balance, and a new, current rate on the extra borrowing.
| Scenario | What typically happens |
|---|---|
| Moving to a cheaper property, borrowing less | Port the existing rate on the reduced balance; may face an early repayment charge on the amount you're not carrying forward |
| Moving to a similarly priced property | Port the full balance and rate, subject to reapplication |
| Moving to a more expensive property, borrowing more | Ported rate applies to the original balance; new borrowing is at the lender's current rate |
Common misconceptions
- "Porting means I don't need to reapply." You almost always do — it's a new application in all but the interest rate
- "If I'm refused, I lose my rate entirely." You may then face the early repayment charge to switch products, or need to find a different lender's deal for the new property
- "Porting is automatic." You need to contact your lender before selling, not after, to check the process and timing requirements
What to do next
Before putting your home on the market, contact your existing lender (or a mortgage broker) to confirm whether your deal is portable, what the reapplication process involves, and what rate would apply to any additional borrowing. Comparing the total cost of porting against simply remortgaging to a new deal elsewhere is worth doing — porting isn't always the cheaper option once fees are factored in.