Can I sell my flat before my lease extension is complete?

You don’t always need to wait for your lease extension to finish before completing the sale of your flat. If you’ve served a valid Section 42 notice and the claim is still live, you can transfer it to the buyer when the sale completes. The buyer can then continue the lease extension from the stage it has reached. 

Whether this works for your sale depends on what you and the buyer agree, how far the claim has progressed, and whether the buyer’s mortgage lender will accept the existing lease.

If you’re planning to sell a flat with a lease extension underway, contact our solicitors for advice on coordinating the claim with your sale.

How to assign a Section 42 notice to the buyer

A Section 42 notice formally starts a statutory lease extension claim for a flat. If the claim is still live when you sell, you can transfer the rights and obligations under the notice to the buyer as part of the lease. This is commonly called assigning the benefit of the Section 42 notice. 

The seller’s and buyer’s solicitors should agree how to document the assignment so it takes effect on completion. If the lease is transferred without the benefit of the notice, the law treats the notice as withdrawn on the date of the transfer with effect from registration at Land Registry in the name of the new owner. Any new claim cannot be commenced until 12 months have passed from the date of the deemed withdrawal.

For more on starting a statutory claim, see our guide to serving a Section 42 notice to extend your lease.

What should you agree with the buyer before completion?

Raise the lease extension with your conveyancer as soon as you decide to sell. The buyer will need to know what stage the claim has reached and what they are taking on. The sale contract should record what you’ve agreed about the claim, including who will:

• Pay the lease extension premium and the legal and valuation costs, including costs already incurred.
• Account for any deposit already paid to the freeholder.
• Deal with the freeholder and take any steps required before the sale completes.

The contract should also deal with what happens if you agree the premium or lease terms before completion, or if the sale is delayed. Give your conveyancer a copy of the Section 42 notice, any counter-notice, and details of the negotiations so far. The buyer’s solicitor will need to see what has been agreed, what remains outstanding, and when the next deadline falls. 

Can the buyer get a mortgage while the lease extension is underway?

The buyer should check their lender’s requirements early. A lender may assess the flat based on the lease as it stands at completion. If the lender requires a longer lease before it will release funds, you may need to complete the extension before or at the same time as the sale.

This is particularly important if the remaining lease term is already affecting the buyer’s mortgage options. Our guide to flat lease extensions explains why the remaining term matters.

What happens to the lease extension after the sale?

The buyer takes over the claim at the stage it has reached. For example, if the freeholder has served a counter-notice proposing a higher premium, the buyer can carry on negotiating from there. The original notice date remains the valuation date, and any statutory deadlines already running still need to be met. 

If a deadline is close to the planned completion date, the solicitors should agree who will take the required step and when. This matters particularly if the sale timetable changes while a deadline is running. 

Can the buyer start their own lease extension after buying the flat?

The two-year ownership requirement for statutory lease extensions was removed on 31 January 2025. A buyer who otherwise qualifies can start their own claim once they are legally entitled to serve notice. If you’ve yet to start a claim, this may be an option if the buyer and their lender are happy to proceed on the existing lease. 

Taking over an existing claim can still make sense if negotiations are well advanced or the original valuation date is favourable. Before deciding, the buyer should check when they could serve a fresh notice, particularly if their purchase is still awaiting registration. It is important to note that if a lease extension claim becomes deemed withdrawn, as mentioned above, a new claim cannot be commenced until 12 months have passed from the date of the withdrawal.

What if you’re negotiating an informal lease extension?

If you’re negotiating directly with the freeholder and haven’t served a Section 42 notice, the statutory assignment procedure doesn’t apply. If the buyer wants to take over those negotiations or rely on terms you’ve already agreed, your solicitor should establish what the freeholder is prepared to agree with the buyer before you commit to the sale terms. 

Selling a flat with a lease extension underway

If you’re selling while a lease extension is underway, tell your conveyancer early so they can coordinate the sale and the claim. That gives both sides time to agree whether the buyer will take over the claim or whether the extension needs to complete before or alongside the sale.

Áine Dillon, solicitor, says:

“If you’re selling with a lease extension underway, tell your conveyancer as soon as you put the flat on the market. That gives both sides time to agree on who will pay the outstanding costs, check what the buyer’s lender requires, and decide who will deal with any deadlines if the sale takes longer than expected.”

If you’re selling a flat with a lease extension underway, our residential conveyancing and lease extension solicitors can work together to handle the sale and, where appropriate, transfer the claim to your buyer on completion.