Buying at auction can be one of the most effective ways to acquire a property quickly, sometimes below market value, and without the prolonged uncertainty of a conventional sale chain. It can also be a fast route to a very expensive mistake if you bid without doing the groundwork. This guide explains exactly how UK property auctions work, what you need to check before you bid, and how to protect yourself on the day.
Two Types of Auction: Unconditional and Conditional
UK property auctions fall into two broad categories, and it is essential to know which type you are entering before you bid.
Unconditional (Traditional) Auctions
When the hammer falls, you exchange contracts immediately. You pay a 10% deposit on the spot and are legally committed to completing — typically within 28 days. Walk away after the hammer falls and you forfeit your deposit and may face a claim for the seller's losses.
This is the traditional auction model used by the major auction houses (Allsotts, Barnard Marcus, SDL, Bond Wolfe, etc.) and by most local and regional auctioneer firms.
Conditional (Modern Method of Auction)
The conditional model, popularised by iamsold and used increasingly by estate agents running "online auctions," works differently. On winning the lot, you pay a reservation fee (typically 3–5% + VAT of the purchase price, often non-refundable) and agree to exchange within 28 days and complete within 56 days.
You are not in exchange when the hammer falls — the reservation fee simply secures your right to proceed. This gives you more time to arrange a mortgage, but the fee is usually non-refundable even if you pull out or the deal falls through for title reasons, which is a significant risk if the legal pack is problematic.
| Feature | Unconditional | Conditional |
|---|---|---|
| Exchange | On the fall of the hammer | Within 28 days |
| Completion | Typically 28 days | Typically 56 days |
| Initial payment | 10% deposit | Reservation fee (3–5% + VAT) |
| Payment if withdrawn | Deposit forfeited | Reservation fee usually lost |
| Mortgage viable? | Difficult — very short timeline | More feasible |
| Finance used | Cash or bridging loan | Mortgage or bridging |
The Legal Pack: Non-Negotiable Reading
Every auctioned property comes with a legal pack — a bundle of documents prepared by the seller's solicitor. It is your equivalent of pre-exchange due diligence. The pack typically includes:
- Title documents — freehold or leasehold title, filed at HMLR
- Lease (if leasehold) — including length of unexpired term, ground rent, service charge history
- Office copies — official title register entries
- Local authority, drainage, and environmental searches — may or may not be included; if not, you have no search information before bidding
- Special conditions of sale — any modifications to the standard terms, including who pays the buyer's premium and any restrictive obligations
- Management information (leasehold) — service charge accounts, building insurance, major works notices
- Tenancy agreements (if tenanted) — including rent, term, and any break rights
- Energy Performance Certificate (EPC)
Read the special conditions carefully. They often contain clauses that impose costs on the buyer beyond the headline price — for example, a requirement to pay the seller's legal costs, a stipulation that the buyer bears the cost of discharging a specific encumbrance, or an obligation to take on an occupier on non-standard terms.
If searches are not included in the pack, factor this into your due diligence. Indemnity insurance in lieu of searches is sometimes acceptable to mortgage lenders but not always.
Instructing a Solicitor Before the Auction
This is not optional. Instruct a solicitor to review the legal pack before auction day. Solicitors experienced in auction purchases can turn around a legal pack review in 24–48 hours. They will identify:
- Title defects (gaps in ownership history, missing documents, overriding interests)
- Flying freehold risks (where part of one property sits over another with no adequate support covenant)
- Short lease issues (fewer than 70 years raises mortgage complications; fewer than 80 years triggers marriage value on lease extension)
- Sitting tenants or occupiers who cannot easily be removed
- Chancel repair liability (older properties, particularly near churches)
- Rights of way and easements that restrict use
- Onerous covenants in the title
The cost of a pre-auction legal review is typically £300–£600. Against a deposit of thousands or tens of thousands of pounds, this is not a sum to economise on.
Getting a Survey Before You Bid
Auction houses will usually grant access for a survey before the sale, though the degree of cooperation varies by seller and property. Always request access — even a brief RICS HomeBuyer Report gives you enough information to judge whether there are major structural issues that would affect your bid.
Common issues found at auction:
- Structural movement or subsidence
- Flat or failing roof
- Japanese knotweed in the garden
- Evidence of damp (see our guide on damp in older properties)
- Asbestos (properties built pre-2000)
- Electrical systems requiring full rewire
If access is refused, you are bidding blind on condition — a risk premium that should be reflected in your maximum bid price.
Financing Your Auction Purchase
For unconditional auctions, a standard residential mortgage is rarely practical — lenders typically need 6–8 weeks minimum from application to completion, and the 28-day completion window is too tight.
Your realistic options are:
| Finance Type | Speed | Cost | Suitability |
|---|---|---|---|
| Cash | Immediate | No interest | Best option if available |
| Bridging loan | 7–14 days to drawdown | 0.5–1.5% per month | Renovations, short-term hold |
| Pre-approved mortgage | Depends on lender | Standard rate | Some lenders, conditional only |
| Developer finance | Case by case | Negotiated | Commercial/semi-commercial lots |
Bridging loans are the most common route for investors and developers at unconditional auctions. You need to speak to a specialist bridging broker before auction day — agree terms in principle, confirm the security will be accepted, and know exactly what the exit strategy is (usually a refinance onto a term mortgage or sale once the property is habitable).
For conditional auctions, a standard mortgage may be possible — but check with your broker that 56 days is achievable given the lender's processing time.
Fees You'll Pay as a Buyer
Headline bid price is not the total cost. Factor in:
| Fee | Amount | Notes |
|---|---|---|
| Buyer's premium | 1–5% + VAT | Payable to auction house on exchange/reservation |
| SDLT (Stamp Duty Land Tax) | 0–12% depending on price and buyer status | FTBs, additional dwellings have different rates |
| Solicitor's fees | £800–£1,500 | Higher than standard due to compressed timescale |
| Pre-auction legal review | £300–£600 | Separate from conveyancing fees |
| Survey | £400–£1,000+ | RICS HomeBuyer or Building Survey |
| Bridging loan arrangement fee | 1–2% of loan | If using bridging finance |
| Bridging interest | 0.5–1.5%/month | For the duration of the bridge |
Always calculate your total acquisition cost before setting your maximum bid.
Auction Day: Step by Step
- Register to bid — most auction houses require ID (passport or driving licence + proof of address) and a signed bidder registration form in advance.
- Know your maximum bid — set it before you walk in. Auction rooms (and live online auctions) are designed to create competitive urgency. Having a hard limit protects you from overpaying.
- Read the addendum — last-minute changes to legal packs or special conditions are published as an addendum on auction day. Always collect or download it.
- Attend or instruct a proxy — you can bid in person, by telephone, online (most houses now offer live online bidding), or through a proxy.
- The hammer falls — on unconditional auctions, sign the memorandum of sale immediately and hand over your 10% deposit by pre-cleared cheque, bank transfer, or debit card.
- Your solicitor is instructed — contact them immediately after exchange so they can begin the completion process.
- Exchange is done; completion is the finish line — ensure your finance is ready to drawdown within the required window.
Common Auction Risks
- Sitting tenants: If a tenant has security of tenure (typically an Assured Tenancy under the Housing Act 1988), you may be unable to obtain vacant possession without a lengthy court process.
- Short or defective leases: A lease under 70 years is a financing problem; under 60 years, many cash buyers will also discount heavily.
- Flying freehold: Where part of a property sits above or below another — common in terraced Victorian and Edwardian houses — without an adequate support covenant, insurance may be required.
- Contaminated land: Especially relevant on former industrial sites or properties near petrol stations.
- Title defects: Missing title deeds, adverse possession claims, unresolved boundary disputes.
When Auction Makes Sense vs Open Market
Auctions are most suitable when:
- The property requires significant renovation and is unlikely to achieve full financing via a standard mortgage
- Speed of purchase is critical
- The property is unusual (listed building, mixed use, commercial) and the open market has limited buyers
- You are an investor buying tenanted buy-to-let with certainty of transaction
The open market is more appropriate if:
- You need mortgage finance and your lender has a long processing time
- You want the ability to renegotiate after a survey
- You are chain-dependent
Conclusion
Buying at auction requires more preparation than a conventional purchase — but done properly, it offers genuine advantages: speed, certainty, and occasional value. The golden rules are simple: read the legal pack with a solicitor before you bid, get a survey if access is available, know your finance before you bid, and set a maximum price and hold to it.
For related reading, see our guides on what to look for in a home survey and how to find and vet a builder for when you're ready to start renovating your new acquisition.