Moving home
A sale and a purchase, usually on the same day, usually with a chain behind each of them. The mortgage question sits underneath both: what happens to the loan you already have, and whether the deal attached to it can come with you.
Get that decided early and the rest of the move is logistics. Leave it late and it becomes the thing everyone is waiting on.
The decision
Which is right depends less on the rate you are on than on whether you are borrowing more, whether an early repayment charge applies, and how well the dates line up.
Take the existing product to the new property. The rate, the lender and the remaining initial period all carry over, and the early repayment charge is not triggered. Most residential mortgages are portable in principle — which is not the same as porting being straightforward.
Keeps your rate · avoids the ERC
Repay the existing loan on completion of the sale and take an entirely new mortgage on the purchase, from any lender. Complete freedom of choice, and any early repayment charge falls due. Often the better answer once an initial period is close to ending.
Full choice · ERC may apply
Stay in the existing mortgage and rent the property out under consent to let, buying the new one on a separate mortgage. The lender's permission is required, it is usually time-limited, and being a landlord has tax and regulatory consequences of its own.
Needs the lender's consent
Porting
It is a common misunderstanding that a portable mortgage moves with you as a matter of right. What is portable is the product — the rate and its terms. The lending itself is underwritten again from the beginning: income verified, credit searched, affordability assessed against current criteria, and the new property valued and accepted as security.
That means a port can fail for reasons that have nothing to do with the rate. Income that has changed shape since you last applied, a lender whose criteria have tightened, or a property the lender will not lend on — a flat above commercial premises, a non-standard construction, a short lease — will each stop it.
Borrowing more complicates it further. The additional amount is not on your existing rate; it is a second product priced at today's rates, which leaves you with two parts on two rates ending on two different dates. That is workable, but it needs planning, because those dates want to be brought back together at the next switch.
Timing is the last constraint. Porting means redeeming the loan on the sale and re-drawing it on the purchase, and lenders allow only a limited window between the two. Completing both on the same day, which most people do, sidesteps the issue entirely.
Ask your lender for its porting criteria in writing before you offer on anything — the answer often decides which properties are worth viewing.
If the new property is cheaper and you are borrowing less, a partial early repayment charge can still apply to the reduction.
Sequence
The two transactions have to converge on a single day. Almost every delay in a move traces back to something that could have been started earlier.
Not what you borrowed last time. Criteria change, income changes, and the equity released by your sale changes the deposit you are working with. This sets the ceiling for everything that follows.
Confirm whether an early repayment charge applies today, what your lender's porting criteria are, and what the wider market would offer on a new mortgage. The three answers together make the decision.
An offer accepted on your sale and an offer accepted on your purchase. Until both exist there is no chain, and until there is a chain there is no completion date to work back from.
Whether you are porting or starting fresh, the lender underwrites the case and values the new property. The offer is issued to you and to your conveyancer, and has an expiry date that the chain has to fit inside.
Exchange makes both contracts binding and fixes the date. On completion the sale redeems the old mortgage, the new lending draws down, and the difference moves through your solicitor's client account.
What derails a move
Questions
Usually the product is portable, but porting is a fresh application. The lender reassesses your income and affordability against its current criteria and has to accept the new property as security. Most ports succeed; the ones that fail generally do so because income has changed shape, criteria have tightened, or the property is one the lender will not lend on.
The extra is a separate product at today's rates, sitting alongside the ported part. You end up with two balances on two rates, and often two different end dates. That is manageable, but it is worth deliberately choosing an additional product whose end date can be brought back into line with the first at the next switch, rather than accepting whatever term is offered.
Not necessarily, but buying first means funding two properties at once, which is why bridging finance exists and why it is expensive. Most people complete on both the same day. If the chain will not allow it, the options are a short bridging facility, a temporary let of the old property with the lender's consent, or renting between the two — each with a real cost attached.
With the lender's permission, yes — that is consent to let. It is usually granted for a limited period and sometimes at a different rate. Beyond that you would need a buy-to-let mortgage. Either way you become a landlord, with the tax treatment, safety obligations and energy performance requirements that come with it, so it is a decision worth taking on more than the mortgage arithmetic alone.
From exchange of contracts, not from completion. Once contracts are exchanged the risk in the property is generally yours even though you do not own it or hold the keys. Your conveyancer will remind you, but the policy needs to be arranged in advance rather than on the day.
The mortgage is rarely the long pole. Between an offer accepted and completion, a straightforward chain commonly runs to a few months, dominated by conveyancing, searches and the pace of the slowest party. A mortgage offer is typically valid for around six months, which is usually enough — but not always, which is why the offer's expiry date is worth watching from the start.
Keep reading
Your home may be repossessed if you do not keep up repayments on your mortgage. Figures shown on this site are illustrative estimates and do not constitute advice or an offer of credit.
Next step
Tell us what you owe, what you are on and where you are going. We will tell you whether porting is the right call before you offer on anything.
