Conveyancing After an Auction Sale: The 28-Day Timeline

Selling a property at auction is one of the fastest and most certain ways to achieve a sale. But that speed comes with a trade-off: once the hammer falls, you are locked into a tight 28-day timeline to complete the transaction \u2014 and there is very little room for error.

In a standard private treaty sale, the period between accepting an offer and completing can stretch to 12 to 16 weeks. At auction, that window compresses to just four weeks. If either party fails to meet the deadline, the consequences are severe: deposit forfeiture, penalty interest, and potential legal action.

This guide explains exactly what happens after the hammer falls, what the seller needs to prepare before the auction, and how to navigate the 28-day completion timeline without delays.

How auction sales differ from private treaty sales

In a private treaty sale \u2014 the way most UK homes are sold \u2014 the buyer makes an offer, the seller accepts, and then both parties instruct solicitors to begin the conveyancing process. Exchange of contracts typically happens 8 to 14 weeks later, and either party can withdraw at any point before exchange without penalty. According to Propertymark, around 30% of agreed sales fall through before exchange.

An auction sale works differently. Contracts exchange immediately when the auctioneer\u2019s hammer falls. The buyer signs the contract and pays a 10% deposit on the spot. From that moment, both parties are legally committed. There is no cooling-off period, no renegotiation, and no option to pull out without serious financial consequences.

This means that all the legal preparation which normally happens after an offer is accepted must instead happen before the auction takes place. The seller\u2019s solicitor prepares the legal pack in advance, and the buyer\u2019s solicitor reviews it before bidding. On auction day, both sides should already know exactly what they are committing to.

The 28-day completion timeline: day by day

The Common Auction Conditions, published by RICS and widely adopted by auction houses across England and Wales, set a standard completion period of 28 calendar days (20 working days) from the auction date. Here is what typically happens during those four weeks.

As you can see, there is no slack in this timetable. In a private treaty sale, a delay of a week or two is annoying but manageable. In an auction sale, every day counts because the 28-day deadline is contractually fixed.

What sellers must prepare before the auction

The single most important thing a seller can do to ensure a smooth auction completion is to prepare a comprehensive legal pack well in advance. This pack is made available to prospective buyers and their solicitors before the auction so they can carry out due diligence in advance of bidding.

The auction legal pack

A complete auction legal pack should include:

• Title register and title plan from HM Land Registry, confirming ownership and any restrictions or charges on the property.
• Contract for sale drafted by the seller\u2019s solicitor, incorporating the general and special conditions of sale.
• Special conditions of sale covering any property-specific matters such as known defects, rights of way, restrictive covenants, or overage provisions.
• The TA6 Property Information Form and TA10 Fittings and Contents Form, completed by the seller.
• Property search results \u2014 local authority search, drainage and water search, environmental search, and any additional searches relevant to the property\u2019s location (such as mining or chancel repair searches).
• Energy Performance Certificate (EPC), which is a legal requirement for marketing any property for sale in England and Wales.
• Planning permissions and building regulations certificates for any work carried out on the property.
• For leasehold properties: the lease itself, the TA7 Leasehold Information Form, and a management information pack from the freeholder or managing agent.

Preparing this pack typically costs between \u00a3500 and \u00a31,500, depending on the property type and the solicitor\u2019s fees. The seller bears this cost regardless of whether the property sells at auction.

Why a thorough legal pack matters

A complete and transparent legal pack serves two purposes. First, it gives prospective buyers the confidence to bid, which typically drives up the final price. Buyers who cannot review the legal position before the auction will either bid lower to account for unknown risks or will not bid at all. Second, it reduces the chance of post-auction complications. If the legal pack is incomplete, the buyer\u2019s solicitor may raise queries during the 28-day window that are difficult to resolve quickly, putting completion at risk.

The seller\u2019s conveyancing checklist before auction day

If you are selling a property at auction, your solicitor will guide you through the preparation. But it helps to understand what needs to happen and when.

What happens on auction day

On auction day, the property is offered for sale either in a physical auction room or via an online platform. The auctioneer opens bidding at or below the guide price, and bidders compete until no further bids are received. If the final bid meets or exceeds the seller\u2019s reserve price, the auctioneer declares the property sold.

At that moment, contracts exchange. The buyer signs the auction contract (which incorporates the special conditions from the legal pack), pays the 10% deposit (or the minimum deposit specified in the conditions), and receives a memorandum of sale. The 28-day completion countdown begins.

If bidding does not reach the reserve price, the auctioneer will withdraw the lot. The seller is under no obligation to accept a bid below the reserve. However, negotiations can continue after the auction, and a post-auction deal can be struck \u2014 though this is a private treaty sale with different terms.

Potential problems during the 28-day window

Even with thorough preparation, issues can arise during the completion period. Here are the most common problems and how sellers can mitigate them.

Buyer mortgage delays

If the buyer is purchasing with a mortgage, the lender must complete its valuation and issue a formal mortgage offer within the 28-day window. This is achievable but tight. Some lenders are slow to instruct valuers or to process applications, particularly for non-standard properties. If the buyer\u2019s mortgage is not in place by day 28, they may request an extension \u2014 but the seller is not obliged to grant one.

As a seller, you cannot control the buyer\u2019s mortgage arrangements. But having a complete legal pack with all searches and documentation ready means the lender has everything it needs from your side, reducing the chance of delays caused by missing information.

Title issues discovered late

Occasionally, the buyer\u2019s solicitor discovers a title issue during the post-auction review that was not apparent from the legal pack. This might include a missing easement, an unregistered interest, or a discrepancy between the title plan and the physical boundaries. Resolving these issues within 28 days can be challenging.

The best defence is preparation. Before the auction, ask your solicitor to carry out a thorough review of the title and flag any potential issues. If there are known problems, disclose them in the special conditions of sale so buyers factor them into their bids rather than discovering them after exchange.

Leasehold complications

Leasehold properties are more complex to sell at auction because of the additional documentation required. The management information pack from the freeholder or managing agent can take 2 to 4 weeks to obtain, and if it is not included in the pre-auction legal pack, it may not be ready in time for completion.

If you are selling a leasehold property at auction, order the management pack at the same time as you instruct your solicitor \u2014 ideally 8 to 10 weeks before the auction date. Ensure the pack includes up-to-date service charge accounts, ground rent details, building insurance information, and details of any planned major works.

Chain complications on the seller\u2019s side

If you are selling at auction but also buying another property through a private treaty sale, you need to coordinate carefully. Your onward purchase may not complete within 28 days, which could leave you without somewhere to move to on completion day. Consider whether you need a bridging arrangement or temporary accommodation, and discuss timing with your solicitor well before the auction.

Penalties for late completion

The Common Auction Conditions and the Standard Conditions of Sale set out clear penalties for failing to complete on time:

• Interest on late completion: The party at fault must pay interest on the purchase price at a rate specified in the contract (typically 4% above the Bank of England base rate) for every day completion is late.
• Notice to complete: If one party fails to complete on the contractual date, the other can serve a notice to complete, giving 10 working days to finalise the transaction.
• Rescission: If the defaulting party still fails to complete after the notice period, the innocent party can rescind the contract. If the buyer defaults, the seller retains the 10% deposit and can re-sell the property. If the seller defaults, the buyer can recover the deposit and claim damages.
• Damages: The innocent party can pursue the defaulting party for losses arising from the breach, including any price difference on re-sale, additional legal costs, and wasted expenditure.

These penalties give both parties a strong incentive to complete on time. For sellers, the 10% deposit provides significant security, but the goal should always be a smooth, on-time completion.

Modern auction methods: the 56-day alternative

Traditional (or "unconditional") auctions operate on the 28-day model described above. However, a growing number of properties are now sold through modern method of auction (also called "conditional auction"), which works differently.

In a modern method auction, the winning bidder pays a reservation fee (typically 2\u20135% of the sale price plus VAT) rather than a traditional 10% deposit. The buyer then has a longer period \u2014 usually 56 days \u2014 to exchange contracts and complete. During this extended period, the buyer can arrange a mortgage, carry out a survey, and conduct full due diligence.

From the seller\u2019s perspective, the modern method offers less certainty than a traditional auction because the buyer has not yet exchanged contracts. If the buyer withdraws, they forfeit the reservation fee, but the seller must re-market the property. Traditional auctions remain the preferred choice for sellers who want maximum certainty and speed.

How auction conveyancing compares to standard conveyancing

Tips for sellers to ensure a smooth auction completion

Based on the tight 28-day timeline, here are the practical steps sellers should take to minimise the risk of problems.

1. Instruct your solicitor at least 8 weeks before the auction. This gives enough time to prepare the legal pack, order searches, and deal with any issues that arise.
2. Order searches early. Local authority searches are the slowest element. Order them as soon as you instruct your solicitor so results are back well before the legal pack deadline.
3. Complete the TA6 and TA10 thoroughly. Use our conveyancing checklist for sellers to make sure nothing is missed. Vague answers create uncertainty for buyers and their solicitors.
4. Disclose known issues in the special conditions. Transparency builds buyer confidence and prevents post-auction disputes. If there is a known boundary issue, missing certificate, or restrictive covenant, state it clearly in the special conditions.
5. Ensure your solicitor is available during the 28-day window. Check that your solicitor will not be on holiday or otherwise unavailable during the completion period. Slow responses from the seller\u2019s solicitor are one of the most common causes of delayed auction completions.
6. Have a plan for completion day. Know where you will be, ensure you have somewhere to move to, and confirm arrangements for handing over keys.

Sources and further reading

• RICS (Royal Institution of Chartered Surveyors) \u2014 Common Auction Conditions and guidance on auction practice (rics.org)
• The Law Society \u2014 Standard Conditions of Sale, Conveyancing Quality Scheme, and property forms guidance (lawsociety.org.uk)
• HM Land Registry \u2014 Title documents, registration requirements, and OS1 priority searches (gov.uk/government/organisations/land-registry)
• National Association of Valuers and Auctioneers (NAVA) \u2014 Code of practice for property auctioneers
• Propertymark \u2014 Research on fall-through rates and auction market data (propertymark.co.uk)
• The Property Ombudsman \u2014 Guidance on auction conduct and consumer protection (tpos.co.uk)
• Gov.uk \u2014 Guidance on buying and selling property, including Energy Performance Certificates and consumer rights (gov.uk)

Frequently asked questions