Porting a mortgage when you move: refund windows, dates and what we do

Porting a mortgage at a glance

What do six lenders publish about porting when you move?

Each lender sets its own porting rules, and they are in your offer or terms. This is what six lenders say on their own public pages, checked on 29 October 2026. Lenders change these rules, so your own documents win. No rates or products are shown.

Read the early repayment section of your own offer before your sale date is fixed. If it names a window, put those months into the checker as “Another lender”.

Does my lender have to let me port?

No. A port is a new application for a new home. Nationwide says you “might be able to” port, and you apply again to its current criteria. HSBC says you must meet its affordability criteria, and the new home its lending and valuation criteria.

The FCA’s rules let a lender skip the full affordability check on a port if you borrow no more and nothing in the deal changes in a way likely to matter for affordability (MCOB 11.6.3R). The lender can still check. If you borrow more, that exception no longer applies, and the lender must check you can afford the new mortgage as a whole.

One case the Financial Ombudsman decided in August 2025 shows how this can go. A lender offered to port only part of what a buyer needed for her next home, after checking affordability. She sold, paid the charge, and the complaint was not upheld.

What if I need to borrow more, or less, on the new home?

More. The lenders in the table above port your current deal and add the extra as a separate deal at the rates on offer when you apply, after affordability checks. So you may end up with two parts, each with its own rate and end date. Your offer will show both.

Less. If you port less than you owe, the charge can apply to the part you repay. Santander says it refunds part of it; YBS says it refunds the charge “on the part you’ve moved”; NatWest says a charge may apply if you port only part. HSBC says a full refund needs the same amount, at the same rate and with the same rate expiry date.

The same. Santander says you won’t pay a charge to port a fixed rate for the same amount, when you sell and buy on the same day.

In 2024 the Ombudsman looked at a couple who ported less and paid part of the charge. Their mortgage papers said a charge applied, and the complaint was not upheld beyond a small payment for poor service.

Can I extend my mortgage offer if completion slips?

Sometimes, and only the lender decides. A ported mortgage still comes with a new offer for the new home, with its own end date. Two lenders publish their extension rules:

• NatWest: “You can apply to extend your mortgage offer by one month.”
• TSB: up to 4 weeks, only once the offer has expired, if your conveyancer can confirm completion in that time, and with no changes to the application.

Others, such as Nationwide on new-build applications, offer no extension. Offer lengths by lender are in our mortgage offer guide, linked at the end of this page.

A new build is where this bites most: your sale can complete long before the home is finished. Your refund window and your offer end date both run from fixed dates, so check both with your lender before you exchange on the sale. For the developer’s long-stop date, see new-build conveyancing.

Where do we come in when you port?

The port itself is between you and your lender, through your broker if you use one. Our part is the legal work on both homes. On one file we:

• get the figure to pay off your mortgage on the home you are selling;
• check your mortgage offer and report to your lender;
• agree exchange and completion dates that work for both sides, with the other solicitors along the chain;
• on completion day, repay the mortgage on the home you are selling and pay the seller’s solicitor for the one you are buying.

When both sides are ready, we usually exchange contracts on your sale and your purchase on the same day and fix one completion date. That is the simplest way to avoid a gap.

We act for your lender as well as you if your lender has us on its panel. We check your lender when we quote.

Your money: send your deposit at least 1 working day before exchange, and the rest at least 1 working day before completion.

Where do ports go wrong in a chain?

1. The sale completes, the port is turned down, and the charge is already paid. A port is a new application, and the lender can say no or offer less (see above).
2. The new build finishes months after the sale. Santander gives 6 months on a new build, not 3. Put both completion dates in the checker.
3. The buyer ports less than they owe and is surprised by a charge. A charge can apply to the part you repay.
4. The new offer runs out before completion. See the extension rules above, and the mortgage offer guide.
5. The chain collapses after the lender has agreed the port. If your move falls through, you pay the File Opening Fee (Non-refundable) and costs already paid out, and the rest is refunded or carried over to your next property. This does not cover charges from your lender, such as an early repayment charge.

Is porting any different for a move to or from Wales?

No. Porting is part of your mortgage contract, so the lender’s rules above apply the same way in Wales.

What changes is the tax on the home you buy. In Wales it is Land Transaction Tax, not Stamp Duty. The return and payment go to the Welsh Revenue Authority within 30 days of the day after completion. In England, the Stamp Duty return is due within 14 days of completion.

12 of the 141 sale-and-purchase quote requests we received were for a home in Wales (website quote requests, 2 Sep–29 Oct 2026).

Which fee lines does a port touch on a sale and purchase?

Our ranges are in the fee box below, each plus VAT. The selling range is for a sale with one registered mortgage to redeem, and includes the Mortgage Redemption Fee: the work of paying off the old mortgage. The buying range is for a purchase with one mortgage, and includes the Mortgage Handling/Admin Fee and the Lender Portal Management Fee: the lender work on the new mortgage, ported or not.

Because your sale and purchase run on one file, your quote charges the File Opening Fee (Non-refundable) and your identity checks once.

Kept apart from our fees: the government charges (Stamp Duty Land Tax in England or Land Transaction Tax in Wales, and the HM Land Registry fee), and anything charged by your lender, not us, such as an early repayment charge or a product or arrangement fee (the amounts are in your offer). We give you a written, itemised quote before you instruct us. For a figure now, use our conveyancing cost calculator.

What happens next

• Conveyancing for buying and selling
• Property chains: where you sit and what a delay costs
• Paying off your mortgage when you sell
• New-build conveyancing
• More guides, explained