What if my mortgage offer may expire before completion?

Which date should I check?

Use the formal mortgage offer, rather than an earlier Agreement in Principle. MoneyHelper explains that these are different stages: an AIP is provisional, while the offer follows the lender’s application assessment. If you are still at the earlier stage, see our AIP preparation guide.

Find the expiry date in your offer and ask the lender or your existing mortgage advisor to clarify anything unclear. Keep the lender’s name, document date and any later correspondence together. Do not calculate a deadline from a general online timetable.

Nationwide’s first-home guide illustrates why the actual terms matter: its standard and new-build offers have different validity and extension arrangements. Another lender’s process may differ.

What should I prepare before asking for more time?

If completion looks likely to run beyond your offer deadline, contact your lender or existing mortgage advisor promptly. MoneyHelper explains that a lender does not have to extend an offer; if it expires, a new application may be needed.

Prepare a short note for that conversation:

• Dates: the offer expiry and the latest proposed completion date. Mark an unconfirmed date as provisional.
• Delay: what you have been told is outstanding, who told you and when.
• Changes: anything that has changed in your income, spending or purchase plans since the application.
• Questions: what you need the lender to confirm and when you should follow up.

Nationwide asks extension applicants for the reason, whether contracts have been exchanged, and changes to income or outgoings. Treat that as an example: ask your own lender which details and documents it needs, and use its secure process to supply them.

Ask: “Is an extension available for this offer? What checks or documents are needed? Could the terms or costs change? How will you confirm the decision?” Keep an unanswered request marked as pending.

What should I tell my conveyancer before exchange?

Share the offer deadline and any confirmed update with the legal professional handling your purchase. Ask how the proposed completion date and outstanding legal work fit with it.

For England and Wales, GOV.UK explains that exchange creates a legal commitment. Your legal representative should advise when you are ready; a confirmed mortgage is among the checks. Ask a local legal professional about the process elsewhere in the UK.

Do not treat an extension request as permission to exchange. Ask your conveyancer what must be resolved before you commit. If you have already exchanged and timing is at risk, contact both your conveyancer and lender or advisor promptly.

Keep a dated follow-up record

The illustration pairs an offer document with a calendar and key: an offer deadline and a planned moving date are separate pieces of information. Use one note with these headings:

• Question and recipient: which point needs an answer, and from whom?
• Response: the date, person and written confirmation received.
• Still outstanding: what remains unresolved?
• Next action: who will do it and the agreed follow-up date?

For example, your conveyancer says a search is outstanding but cannot confirm completion. Record completion as “to confirm”, tell your lender about the timing concern and ask what happens next. An estimated date or a conversation alone is not a confirmed extension.

For wider preparation, return to our buying-a-home mortgage guide. For an active application, speak to the lender or advisor already handling it. If you want to discuss mortgage options, the purchase callback form explains referral to MGI Network Ltd, the advice partner. A callback does not extend an offer; keep documents and account details out of the optional notes.

Sources

• MoneyHelper: how long do mortgage offers last? — offer stages, expiry and extension limits.
• Nationwide: how to buy your first home — an example of lender-specific offer and extension arrangements.
• GOV.UK: how to buy a home — legal readiness for exchange in England and Wales.

Information checked 9 November 2026. General information, not a personal mortgage recommendation.