Borrowers with a good rate and an early repayment charge understandably want to keep what they have when they move. Porting is the mechanism for that, and it is genuinely useful. It is also widely misunderstood, because the word suggests the mortgage travels with you when what actually travels is the interest rate.
Looking for advice on your own situation rather than the general picture? Our remortgage and moving home advice page is the place to start, or you can talk it through with an adviser using the form below.
What porting actually means
Porting means carrying your existing mortgage product — the rate and its terms — across to a new property. The loan on the old property is repaid when you sell, and a new loan is advanced on the new property, with the same product applied to it.
That distinction matters because it explains everything else. Since a new loan is being advanced, the lender is making a fresh lending decision, and you have to satisfy its current criteria.
You are applying again
A port is a new application. The lender will assess your income and affordability as it stands now, run a credit search, and value the new property. Criteria may have changed since you first borrowed, and so may your circumstances.
This is the part that surprises people. Having an existing mortgage in good order does not guarantee the port will be agreed, and a change of job, a drop in income, a new credit commitment or a period of adverse credit can all affect the outcome. The new property itself matters too — a lender that was comfortable with your old house may not be comfortable with a flat above commercial premises or an unusual construction type.
When the new home costs more
Most moves involve borrowing more. The usual structure is that your existing product is ported across on the original balance, and the additional amount is taken as a second part on whatever rate is currently available. You end up with one mortgage made up of two parts on different rates, often with different end dates.
Different end dates are worth planning around, because they can leave you unable to remortgage the whole loan cleanly later without an early repayment charge on one part. Some lenders will align the dates; some will not.
When the new home costs less
If you are borrowing less than before, the surplus is being repaid early, and that can trigger an early repayment charge on the portion repaid. Some lenders allow a reduction within the annual overpayment allowance without charge; others apply the charge to anything above it.
It is worth getting the figure in writing from your lender before committing, because a downsizing move can carry a cost that is easy not to anticipate.
Timing, and why Scottish transactions complicate it
Porting normally requires the sale and the purchase to complete on the same day, because the old loan is repaid and the new one advanced as part of the same movement of funds. Where the dates do not align, the port becomes harder.
Some lenders allow a gap — a window of some months in which you can port after selling — but the length of that window varies, and where it exists you may be without the product in the interim. Where a lender does not allow a gap, a delay on either side of the chain can mean losing the ported rate altogether.
In Scotland the date of entry is fixed in the missives, which gives more certainty than an open-ended chain but also less flexibility if something slips. Your solicitor coordinates the two transactions; the lender coordinates the funds. Both need to know what the other is doing.
Porting is not automatically the cheapest route
Keeping a good rate and avoiding an early repayment charge is often worth a lot. But not always. If the charge is small, or the deal is close to ending, or the additional borrowing you need is large and priced unattractively, moving the whole mortgage to a new lender can work out better overall.
The comparison is between the total cost of porting — the ported rate on the old balance, plus the rate on the additional part, plus any fees — and the total cost of a new mortgage elsewhere including the early repayment charge. It is arithmetic rather than instinct, and it goes both ways.
Before you offer on anything
The useful sequence is to establish what you could borrow now, whether your lender will port, and what the additional borrowing would cost — before you are committed to a purchase. In a Scottish transaction the gap between an accepted offer and a binding contract can be short, so that groundwork is better done early.
Common questions
This guide is general information, not regulated financial advice, and reflects our understanding of the rules at the date shown. Tax treatment depends on individual circumstances and may change. Your home may be repossessed if you do not keep up repayments on your mortgage. Not all buy to let mortgages are regulated by the Financial Conduct Authority.