Key Takeaways
An accepted offer in England is agreed “subject to contract”, so nothing is binding until exchange of contracts. In between, your solicitor completes the legal work, you commission surveys and finalise funds, and any issues are negotiated.
Exchange
When the deal becomes legally binding
114 days
Black Brick average from offer accepted to completion in 2025, versus 174 days across London (Rightmove, July 2026)
10%
Typical deposit paid at exchange
- Until exchange, either side can walk away, and the seller can still accept a higher offer.
- The first 48 hours matter. Instruct a prime London solicitor, clear funds checks, ask for exclusivity.
- A £2m+ home needs deeper checks: an RICS Level 3 survey, specialist reports and a close legal review.
- Survey findings can reduce the price, when backed by evidence and contractor quotes.
- Prepared, chain-free purchases move faster. Our clients averaged 114 days from offer to completion in 2025, two months quicker than the London average of 174 days.
Having an offer accepted on a London home feels like the finish line. In England it is closer to the starting gun. Nothing is legally binding until contracts are exchanged, and the weeks in between are where good purchases are protected, improved or lost.
At £2m and above, the stakes in that period rise sharply. The legal work is more involved, the buildings are older or more complicated, the tax bill runs well into six figures and the seller often has other interested parties waiting in the wings. This guide explains what happens between “offer accepted” and the day you collect the keys, how long each stage takes, and where we see buyers gain or lose ground. If you are earlier in your search, start with our guide to the prime London buying process.
Why an Accepted Offer Is Not Yet a Deal
In England and Wales, offers, acceptances and correspondence about price are all made subject to contract. Until contracts are exchanged, the seller can accept a higher offer from someone else, which is known as gazumping, and the buyer can reduce their offer or walk away. Both are legal. Scotland works differently, with earlier certainty for both sides, which is one reason transactions there complete so much faster.
The Government wants to change this. Its home buying and selling reform roadmap, published in June 2026, proposes upfront “sales packs” before a property is listed and, later, binding conditional contracts shortly after an offer is accepted. None of this is law yet. Binding contracts will not be required until sales packs are embedded, and legislation is planned for the end of this Parliament. For now, anyone buying in London operates under the current rules.
We have seen the consequences from both sides of the table. When we viewed a house on Ilchester Place in Holland Park, it was already under offer to another buyer at £16.5m, but with a delayed completion. We offered £16.25m with a five-day exchange and, helped by our relationship with the selling agent, the seller chose certainty over the higher figure. In Notting Hill and St John’s Wood we have secured properties for clients that were under offer to other parties, exchanging within 48 hours. An accepted offer with a slow or uncertain timetable is a vulnerable one.
Read the case studies: Ilchester Place, Holland Park | Arundel Gardens, Notting Hill | Boydell Court, St John’s Wood
The First 48 Hours After Your Offer Is Accepted
The pace you set in the first two days tells the seller and their agent how seriously to take you. The selling agent will issue a memorandum of sale to both sets of solicitors, setting out the price, the parties and any agreed terms. From there, the priorities are:
- Instruct a solicitor who does prime London work. A firm used to listed buildings, complex leases and international clients will spot problems sooner and move faster. Ideally, they are lined up before you offer.
- Clear anti-money laundering checks early. Estate agents, solicitors and lenders must all verify your identity, your source of funds and source of wealth. For buyers whose wealth comes from a business sale, an inheritance or overseas assets, gathering this evidence can take longer than the legal work itself.
- Ask for exclusivity. A written agreement that the seller will not negotiate with anyone else for a fixed period is the closest thing to protection England currently offers. More on this below.
- Book the surveys. Good surveyors in prime London are busy. Booking on day one rather than day ten can take a week or more out of the timetable.
- Agree a target timetable. Dates for draft contracts, survey results, exchange and completion give everyone something to work towards, and make it obvious early if one side is dragging their feet.
- Brief your lender, if you are borrowing. The lender will arrange its own valuation before issuing a formal mortgage offer.
Buying a prime London property? We can line up the right solicitor, surveyors and specialists from day one. Speak to our team about protecting your purchase
Protecting the Deal: Exclusivity and Momentum
An exclusivity agreement, sometimes called a lock-out agreement, is a written promise from the seller not to negotiate with other buyers for a set period, often a few weeks, while you carry out surveys and legal work. Some are backed by a deposit from the buyer, and the terms vary considerably, so your solicitor should draft or review it. Asking the agent to “take the property off the market” is not the same thing. It is a courtesy, not a commitment.
Exclusivity is usually earned rather than demanded. Sellers grant it to buyers who look certain to proceed: funds evidenced, solicitor instructed, surveys booked and a realistic timetable proposed. The Government’s roadmap also promotes the voluntary use of reservation agreements, where buyer and seller each commit to the transaction with money at stake, although these remain uncommon in the prime market.
Even with exclusivity in place, momentum is the real protection. Deals that drift give sellers time to have second thoughts, give rival buyers time to appear, and give any change in the market time to work against you. Much of what a buying agent does in this period is unglamorous: chasing replies, keeping solicitors, surveyors and the selling agent aligned, and making sure small questions do not become long delays.
Due Diligence on a £2m+ London Property
Prime London homes are rarely simple. Many are period buildings that have been extended, converted, dug down or remodelled more than once, and a large share of apartments sit in managed buildings with long and detailed leases. Due diligence therefore runs on two tracks at once: the legal work and the physical inspection.
The legal work
Your solicitor will review the draft contract and title, order searches, and raise enquiries with the seller’s solicitor. On a prime purchase, the questions that most often matter are:
- Consents for past works. Planning permission, building regulations sign-off, listed building consent and any party wall awards for extensions, basements, loft conversions and internal alterations.
- The title. Restrictive covenants, rights of way, and any estate management schemes, which are common on the great London estates.
- The lease, for apartments. Remaining term, ground rent, service charge history, the sinking fund, planned major works, restrictions on alterations, pets or letting, and how well the building is run. Our leasehold vs freehold guide and guide to service charges cover this in more depth.
- Building safety, for taller blocks. In buildings of at least 11 metres or five storeys, the Building Safety Act 2022 affects who pays for remediating historic safety defects, and the seller should provide the relevant certificates.
- What is included. Fixtures, fittings and any furniture being sold with the property, which should be listed precisely.
The physical inspection
A lender’s valuation is not a survey. At this level, most buyers should commission an RICS Level 3 survey, the most detailed inspection available, and add specialist reports where the property calls for them. Our guide on why a building survey matters before exchange explains what each level covers.
| Check | When it matters most |
|---|---|
| RICS Level 3 survey | Almost always on period, altered or larger homes |
| Structural engineer | Cracking, basements, removed walls, garden or boundary walls, subsidence history |
| Mechanical and electrical (M&E) survey | Lifts, air conditioning, pools, home automation, new builds |
| Drainage CCTV survey | Older houses, basements, large gardens with mature trees |
| Measured survey | Whenever the price was negotiated on a price per square foot basis |
| Specialist reports | Damp and timber, roofs, asbestos in older buildings, heritage advice for listed homes |
Surveyors are paid to be thorough, and a long list of observations on a period house is normal. The skill lies in separating the routine from the issues that genuinely change the value or the cost of ownership, and getting a credible cost for anything significant before exchange.
When the Survey Finds Something
If the survey or legal work uncovers a material issue, there are several ways to deal with it: the seller repairs it before completion, the price is reduced, part of the price is held back until work is done, insurance covers a specific legal gap, or, if the problem is serious enough, you withdraw. Which is right depends on the issue, the property and how competitive the sale was.
How you raise it matters as much as what you ask for. A last-minute price cut with no evidence behind it, known as gazundering, tends to harden sellers and can collapse a deal. A request backed by a specialist report and a contractor’s quote is far harder to dismiss, and keeps the relationship intact.
Two recent examples
In Totteridge, our offer of £2.6m was accepted on a house our clients had found themselves. The survey flagged that a garden wall needed further investigation, so we arranged for a structural engineer to inspect it, obtained a quote for the works, and negotiated a further £25,000 off the price. In total, our clients bought 6.4 per cent below the asking price. Read The Pastures case study.
On a freehold house in a private gated road in St John’s Wood, we had already negotiated the price from £4.5m to £4.2m. Detailed quotes for our client’s planned works then supported a further £50,000 reduction, agreed the day before exchange. Read the Regents Mews case study.
Expert negotiation can make the difference. On average, we secure properties 8 per cent below the asking price. Discover how Black Brick can represent you
Funds, Finance and Tax Before Exchange
Everything needed to complete has to be in place before you exchange, because exchange commits you to paying in full on the agreed date.
- Mortgage buyers need a formal mortgage offer, not just an agreement in principle. If the lender’s valuation comes in below the agreed price, the options are to fund the gap, renegotiate on the strength of the valuation, or try another lender. Private banks often lend on wider terms at this level. Our guide to cash vs mortgage purchases sets out the trade-offs.
- Cash buyers need funds available in the UK in time for the deposit and completion. International transfers and large movements between institutions can take longer than expected, and currency moves between exchange and completion are a real exposure for buyers funding from abroad.
- Companies and overseas entities face extra steps. An overseas entity must be registered on the Register of Overseas Entities before it can be registered as the owner of UK property, and homes held in a company can attract the Annual Tax on Enveloped Dwellings. See our ATED guide.
Stamp Duty on a prime London purchase
Stamp Duty Land Tax must be paid within 14 days of completion, so it belongs in the budget from the outset. The surcharges change the figure significantly: an extra 5 per cent applies if you will own more than one home, and a further 2 per cent if you are not UK resident for Stamp Duty purposes.
| Purchase price | Replacing your main home | Additional home | Additional home, non-UK resident |
|---|---|---|---|
| £2,000,000 | £153,750 | £253,750 | £293,750 |
| £5,000,000 | £513,750 | £763,750 | £863,750 |
| £10,000,000 | £1,113,750 | £1,613,750 | £1,813,750 |
Figures for individual buyers of freehold residential property in England, using the rates on GOV.UK as at October 2026. Reliefs, company purchases and mixed-use property are treated differently. Use our Stamp Duty calculator for your own figures, read our Stamp Duty guide, and take tax advice before you exchange.
Exchange of Contracts: The Point of No Return
Once the legal work is finished, the enquiries are answered, the surveys have been dealt with and funds are ready, your solicitor will arrange exchange of contracts. Signed contracts are swapped, the deposit is paid, traditionally 10 per cent of the price although a lower figure can sometimes be agreed, and the completion date is fixed.
From this moment both sides are bound. A buyer who fails to complete can lose the deposit and be liable for the seller’s further losses. A seller can no longer accept a better offer. Before exchanging, confirm with your solicitor who is responsible for insuring the property until completion, as this depends on the contract and, for apartments, the lease.
Where speed matters, exchange can happen very quickly. On a Grade I listed Georgian villa in Hampstead, the property’s age and location meant a great deal of due diligence, yet we moved from accepted offer to exchange in less than a month. On Hans Place in Knightsbridge, we exchanged in under three weeks. On a gated mews house near Hyde Park, we secured the purchase against three other bidders because the selling agent was confident our client would proceed, and completed an attended exchange, where both sides’ representatives meet in person.
Between Exchange and Completion
The gap between exchange and completion is usually one to four weeks, and exchange and completion can take place on the same day if both sides agree. It is the time to prepare the property for your arrival rather than to reopen negotiations:
- Arrange buildings and contents insurance to start at the right moment.
- Book a pre-completion visit to check that the property and any agreed contents are as expected.
- Set up utilities, security, alarms and access arrangements, particularly if the home will be empty for a while.
- Line up architects, designers or contractors so that any planned works can begin straight after completion.
Completion Day and After
On completion, your solicitor sends the balance of the price to the seller’s solicitor. Once it arrives, ownership passes to you and the keys are released, usually through the selling agent. Your solicitor then files the Stamp Duty return and pays the tax within 14 days, and registers you as the new owner at HM Land Registry.
For many of our clients, completion is the start of the next phase rather than the end. Overseas owners, second-home owners and anyone planning a refurbishment often need someone on the ground from day one. Our Property Management team looks after homes that are lived in, let or left empty, and can be briefed before completion so that nothing falls between the cracks.
How Long Does It Take From Offer Accepted to Completion?
A well-run, chain-free prime purchase in London usually completes within about four months of the offer being accepted, and the quickest in five or six weeks. Exchange often comes within four to 10 weeks. Preparation, finance and the speed of the legal enquiries usually decide where in that range you land.
Across London as a whole, the average is 174 days from sale agreed to completion, or nearly six months, according to Rightmove. Chains, leasehold questions, slow local authority searches and stretched conveyancers all contribute. Across our 26 purchases in 2025, we averaged 114 days from accepted offer to completion, around two months quicker than the London average. Our clients are usually chain-free and proceedable, which makes much of that difference. The timings below are indicative of a well-run prime purchase rather than a promise.
| Stage | Indicative timing | What happens |
|---|---|---|
| Offer accepted | Day 0 | Memorandum of sale issued, solicitors instructed, identity and funds checks begin |
| Exclusivity agreed | Days 1 to 5 | Seller agrees not to deal with other buyers for a fixed period |
| Draft contract and searches | Weeks 1 to 3 | Title, contract package and searches reviewed by your solicitor |
| Surveys and specialist reports | Weeks 1 to 3 | Condition, structure and services inspected, costs obtained for any issues |
| Enquiries, renegotiation and finance | Weeks 3 to 8 | Questions answered, any price adjustment agreed, mortgage offer issued |
| Exchange of contracts | Often weeks 4 to 10 when no chain is involved | Deposit paid, completion date fixed, both sides bound |
| Completion | Usually 1 to 4 weeks after exchange | Balance paid, keys released, Stamp Duty paid within 14 days |
What a Buying Agent Does After the Offer
The selling agent works for the seller and is paid by them. That does not make them obstructive, but it does mean nobody on that side of the transaction is protecting your interests. A buying agent is retained only by you, and the period after an offer is accepted is where that matters most. You can read more about how the two roles differ in our guide to estate agents and buying agents.
Once terms are agreed, we:
- introduce solicitors, surveyors and specialists from our trusted network, matched to the property and the client;
- negotiate exclusivity and a realistic timetable, then hold everyone to it;
- interpret survey findings with you, obtain costs and renegotiate where the evidence supports it;
- keep the selling agent confident that the sale will happen, which is the best defence against gazumping;
- manage the practical details through to completion, and beyond if you need us to look after the home.
The Chambers High Net Worth Guide 2025 noted that “Black Brick maintains meticulous attention to the details of clients’ transactions.” Since 2007, we have acquired more than £2 billion of property for our clients.
Your Questions Answered
No. In England and Wales an accepted offer is subject to contract, so either side can withdraw or change the terms without penalty until contracts are exchanged. The Government plans to introduce binding conditional contracts in future, but they are not yet law.
Yes. Until exchange, the seller can accept a higher or more certain offer, which is known as gazumping. An exclusivity agreement, fast progress and evidence that you are ready to proceed are the best protection.
A well-run, chain-free prime purchase usually completes within about four months of the offer being accepted, and the quickest in five or six weeks. Across London as a whole the average is 174 days from sale agreed to completion, according to Rightmove data published in July 2026. Across our 26 purchases in 2025, Black Brick clients averaged 114 days from offer to completion.
Yes, if the survey reveals something that genuinely affects the value or the cost of ownership. Requests backed by a specialist report and a contractor’s quote are far more likely to succeed than a reduction with no evidence, which can cause the seller to withdraw.
Traditionally 10 per cent of the purchase price, although a lower deposit can sometimes be agreed. A buyer who fails to complete after exchange can lose the deposit and be liable for the seller’s further losses.
In most cases, yes. An RICS Level 3 survey is recommended for older, larger or altered homes, which describes most prime London property. Specialist reports, such as structural, mechanical and electrical, or drainage surveys, are often added depending on what the building contains.
Stamp Duty Land Tax must be paid, and the return filed, within 14 days of completion. Your solicitor normally handles both, so the funds need to be ready alongside the completion money.
A buying agent protects the deal through to completion: introducing solicitors and surveyors, negotiating exclusivity and the timetable, renegotiating on the evidence of the surveys, keeping the selling agent confident and managing the practical arrangements. Unlike the estate agent, they act only for the buyer.
Your Unfair Advantage in Prime London Property
Whether you have just had an offer accepted or are about to make one, we can protect your position through to completion. Since 2007, we have acquired more than £2 billion of property for our clients.
Sources: Rightmove (time from sale agreed to completion, July 2026) | GOV.UK home buying and selling reform roadmap (June 2026) | GOV.UK Stamp Duty Land Tax rates | GOV.UK Register of Overseas Entities. Facts checked 12 October 2026. This guide is general information about buying property in England and is not legal or tax advice. Take advice from a qualified solicitor and tax adviser on your own purchase.
