Sale fell through because of a short lease? Serve a Section 42 notice and assign it to your buyer

If a buyer walked away because of your lease length, you have two main options: finish the lease extension before you re-market, or start the statutory process now by serving a Section 42 notice and pass the benefit of it to your buyer on completion. The second option lets the buyer finish the extension on the terms you've already started, without waiting for a full 6-18 month process before you can sell. It only works if the assignment is done at the same moment as the sale, and if the buyer's lender is comfortable with it.

Key takeaways

• The rights and obligations under a Section 42 notice can be assigned with the lease. If the flat is sold without assigning the notice, the notice is deemed withdrawn (legislation.gov.uk, s.43(3)).
• Serving notice fixes the valuation date: "the clock stops ticking once you serve notice" (MSE). That matters most near 80 years.
• The buyer no longer needs two years of ownership to claim (rule removed 31 January 2025), but taking over your notice can save time.
• Serving the notice costs the seller money up front: own solicitor and valuer, then the freeholder's reasonable costs. How these are shared with the buyer is negotiable.
• Check early with the buyer's conveyancer and lender. Lending policies differ.

Why did my sale fall through on an 88-year lease?

You're not alone. On MSE in December 2025, a seller reported "a sale fell through, and the buyer reportedly cited the short lease" at 88 years (MSE forum). Buyers and lenders look ahead. Mortgage Solutions notes that "lease length can affect marketability and mortgageability and therefore the quality of the security" (Mortgage Solutions). One landlord reported in September 2026 that on a remortgage, "the lender will require a lease extension to 99, 125 or 999 years" (Property118).

Under 80 years the problem is sharper, because marriage value (the share of the value released by the extension that the freeholder is paid) becomes payable. In MSE's estimates, the premium for a £500,000 flat goes from £10,500 at 85 years to £30,500 at 79 years (MSE).

Extend first, or serve the notice and sell?

Assigning makes the sale more complex, and the buyer may ask for a price reduction to reflect the premium still to pay.

How does assigning a Section 42 notice work?

A Section 42 notice (see our Section 42 guide) is the formal claim to a statutory lease extension under the Leasehold Reform, Housing and Urban Development Act 1993. Section 43(3) of that Act says the tenant's rights and obligations "shall be assignable with, but shall not be capable of subsisting apart from, the lease of the entire flat". It adds that if the lease is assigned without the benefit of the notice, the notice "shall accordingly be deemed to have been withdrawn by the tenant as at the date of the assignment" (legislation.gov.uk, text up to date to 23 October 2026).

In practice:

1. You (the seller) serve the notice on the freeholder and any intermediate landlords, with a proposed premium based on a valuer's report. Osbornes lists failing to serve every intermediate landlord as a common defect (Osbornes Law).
2. The sale contract deals with the claim: who pays which costs, who controls negotiations before completion, and what happens to the deposit.
3. On completion of the sale, the benefit of the notice is assigned to the buyer at the same time as the lease is transferred. Osbornes says the benefit "can be assigned to a buyer when the flat is sold" and that "the assignment must be carried out properly".
4. The buyer carries on the claim: negotiating with the freeholder, applying to the tribunal if needed, and completing the new lease.

When should I serve the notice, and what are the deadlines?

Ideally, before you put the flat back on the market, and certainly before exchange, so the buyer's solicitor can see the notice and the freeholder's response. Key statutory timings from LEASE's formal-route page (updated 22 December 2025) and Osbornes:

Sources: LEASE; Osbornes Law.

If neither side applies to the tribunal within six months of the counter-notice, the notice can be treated as withdrawn (Osbornes Law). Withdrawal means paying the freeholder's reasonable costs to that date, and no new notice for 12 months. In a chain, these dates can fall either side of completion, so both conveyancers must track them.

What does it cost the seller, and who pays what?

These are published ranges (HomeOwners Alliance, October 2026). They are indicative; ask for itemised written quotes.

Source: HomeOwners Alliance, updated 22 Oct 2026; deposit also per LEASE. The "who pays" column shows points to agree, not legal rules.

Because the rights and obligations pass with the assignment, ask your conveyancer how the freeholder's costs incurred before completion are dealt with, and whether the deposit is refunded to you, credited to the buyer or reflected in the price.

How will the buyer and their lender see it?

A buyer may welcome a notice already served: it fixes the valuation date and means they don't have to start from scratch. A forum reply in 2023 suggested exactly this: "Ask the seller to start the statutory process before selling, and the buyer completes it" (MSE forum).

Lenders are the harder part, and we found no published lender policy on assigned notices. Ask the buyer's broker, before exchange, whether the lender will lend on the existing lease with a claim in progress or wants the extension completed first. Lending policies differ, and MSE notes that mortgages get harder below 70 years (MSE).

Seller's checklist before re-marketing:

• [ ] Get a valuation of the statutory premium from a chartered surveyor.
• [ ] Ask your solicitor to serve the Section 42 notice on every landlord in the title chain.
• [ ] Agree in the sale contract who pays which costs and how the deposit is handled.
• [ ] Ask the buyer to confirm early that their lender accepts the arrangement.
• [ ] Make sure the assignment of the notice is completed on the same day as the transfer.

FAQ

Can I sell and let the buyer finish the lease extension? Yes, if you serve a Section 42 notice and assign its benefit to the buyer at completion. If the flat is sold without the assignment, the notice is deemed withdrawn. Your conveyancer handles the assignment.

Does my buyer need to have owned the flat for two years? No. The two-year ownership rule was removed on 31 January 2025, so a buyer can serve a notice straight after buying. Taking over your notice keeps your valuation date and saves time.

Is a lease under 80 years mortgageable? Some lenders lend below 80 years, others are cautious; policies differ. A forum user wrote it "is not mortgageable (or that used to be the case)". Ask a broker about your buyer's specific lender.

Who pays the freeholder's costs if I assign the notice? On the statutory route, the claimant is liable for the freeholder's reasonable costs. Since obligations pass with the notice, the sale contract should say how costs before and after completion are split.

Should I extend my lease before selling? Completing first gives buyers certainty; serving and assigning a notice is the faster alternative. Our now-or-wait guide helps weigh timing.

What if the freeholder accepts an informal deal instead? An informal deal can be faster, but check the term, ground rent and fees, and whether the buyer's lender accepts it. See our 10-clause checklist.

Next steps

Gather your lease dates, ground rent terms, the buyer's feedback and your target sale date. Our free Prepare a lease extension quote brief checklist helps you ask a solicitor and valuer for quotes that cover serving and assigning a notice, and Compare statutory and informal routes shows which fits your sale timeline.

Related: Lease extension cost: calculator vs quote vs final bill · Leasehold reform tracker (October 2026)

Important: this is not legal or financial advice. Lease Extension Compass is independent, not a law firm, and doesn't recommend or rank providers. Assigning a Section 42 notice must be done correctly in the conveyancing; an error can cause the notice to be treated as withdrawn. Take advice from a qualified leasehold solicitor and check lender requirements with a mortgage adviser.

Sources

1. Leasehold Reform, Housing and Urban Development Act 1993, section 43 – legislation.gov.uk
2. Lease extension: the formal route, after you serve notice – LEASE (updated 22 Dec 2025)
3. What is a Section 42 notice? – Osbornes Law (updated 14 Aug 2026)
4. Extend your lease – MoneySavingExpert (updated 17 Aug 2026)
5. Lease extension costs – HomeOwners Alliance (updated 22 Oct 2026)
6. Extend now or wait? The short-lease dilemma – Mortgage Solutions (9 Sept 2026)
7. Landlord thread on unextended flats – Property118 (15 Sept 2026)
8. "Extending a lease" – MSE forum (Dec 2025)
9. "Leasehold extension after purchase" – MSE forum (2023)
10. "Overpay mortgage or save for lease extension?" – MSE forum

General information, not legal advice. Rules and deadlines can change by jurisdiction. Check current laws and consult an appropriately qualified professional before acting.