My buyer's mortgage offer is about to expire. What now?

A mortgage offer is the formal document in which a lender commits to lend your buyer a specific sum against a specific property. It is issued once the lender has finished its credit checks, its affordability assessment and its valuation. It carries an expiry date, and the clock generally runs from the date the offer was issued rather than the date your buyer applied.

That last detail catches people out more than any other part of this. By the time everyone starts worrying about the date, several weeks of the offer have usually already gone.

How long does a mortgage offer usually last?

Most high street lenders issue an offer valid for six months. NatWest states it plainly on its own support pages: the offer of loan is valid for six months, with the option to apply to extend by one month. Some lenders work to a shorter window and extend from there, and new build purchases are often given longer because construction timetables slip.

Why do so many offers now run out before completion?

Because sales take longer than offers last. Rightmove reported on 31 July 2026 that the average move in Great Britain takes 216 days from listing to completion, the longest at that point in the year in its records. Only 62 of those days are spent finding a buyer. The remaining 154 come after the sale has already been agreed.

A buyer's offer is usually issued two to four weeks after the sale is agreed. So an average sale now uses roughly five of the six months the offer allows, and any sale running slower than average eats straight through the rest.

• Local authority searches on a slow council can take weeks on their own.
• Leasehold sales wait on a management pack that the seller cannot chase directly.
• A chain moves at the speed of its slowest link, not at yours.

What happens if the offer expires before completion?

The lender withdraws its commitment and your buyer cannot draw the funds until it is reinstated. In practice one of three things follows.

1. The lender extends the existing offer and the original rate holds. This is the common outcome when completion is close and nothing about the buyer has changed.
2. The lender re-issues the offer at current rates, and the buyer's monthly payment changes, up or down.
3. The lender declines and the buyer applies again, which restarts the credit check, the affordability assessment and sometimes the valuation.

Mortgage and lending problems were the single largest cause of failed sales in the second quarter of 2026, at 33% of collapses recorded by Quick Move Now. Most of those were not expiries. It is still the reason to treat the date as a real deadline rather than a formality.

What should I actually do about it?

1. 1. Get the exact expiry date in writing

   Ask your agent to obtain the date from the buyer's broker or lender. Reassurance that there is plenty of time is not a date, and the clock usually started earlier than anyone assumes.

2. 2. Ask the buyer to request an extension now, not at the deadline

   Lenders are not obliged to extend and most want notice. A request made with a month still to run is treated very differently from one made in the final week.

3. 3. Find the real bottleneck

   An expiring offer is a symptom. Ask your solicitor which single item is holding the file: searches, outstanding enquiries, a management pack, or another party further down the chain.

4. 4. Clear the part that is yours

   Return your own enquiries, forms and paperwork the same week they arrive. Sellers hold files up for longer than councils do more often than most people expect.

5. 5. Ask what a re-issued offer would look like

   If rates have moved since the original offer, your buyer needs to know whether the purchase still works at today's pricing before you both spend another month on it.

6. 6. Fix a target exchange date and hold everyone to it

   Once the lender has confirmed an extension, put a target date in writing with your solicitor and your agent, and treat it as a deadline rather than an aspiration.

7. 7. Hold your own spending until the position is confirmed

   Removals deposits, storage bookings and non-refundable dates on your onward purchase can wait until the lender has confirmed your buyer is funded.

What is normal here and what is a genuine red flag?

The left-hand column covers the overwhelming majority of cases. The right-hand column is not proof of anything either. It is the point at which you ask a direct question and expect a direct answer.

Does this week's inflation figure change any of it?

It changes the arithmetic on a re-issue rather than the process. Inflation rose to 2.9% in the year to July 2026, the Bank of England held Bank Rate at 3.75% on 29 July with three of nine members preferring a rise, and the next decision falls on 17 September 2026. If your buyer's offer would need re-issuing after that date, nobody can honestly tell you what rate it will carry. That is an argument for finishing early, not for worrying.

An expiry date is a deadline, not a verdict.

Keep hold of the part that is yours. Your paperwork, your solicitor's responsiveness and your own spending are the three things in this situation that you actually decide.

ValuQ gives UK homeowners free, side-by-side property valuations from competing local estate agents. It is free for homeowners, always, and sellers stay anonymous until they choose which agent to speak to.