Buying a property at auction in the UK is faster and more binding than a standard estate agent sale. This guide walks you through the full process, from browsing the catalogue to picking up the keys on completion day.
What are property auctions and how do they differ from estate agent sales?
A property auction is a public sale where the highest bid wins, subject to a hidden reserve price. Unlike estate agent sales, auctions create a legally binding contract the moment the hammer falls. There is no negotiation, no chain, and no cooling off period.
Estate agent sales in England and Wales typically take 12 to 20 weeks to complete. An auction lot sold under the traditional method completes in 28 days. That speed is why auctions attract distressed sellers, probate estates, and repossessions, and why investors looking for quick deals focus here.
The second core difference is price discovery. An estate agent markets at an asking price the seller will accept. An auction publishes a guide price that is only an indication. The final sale price is set by competitive bidding on the day.
The two main types of UK property auction
The UK has two distinct auction formats. Traditional (unconditional) auctions are the original format. Modern (conditional) auctions, sometimes called “conditional” or “modern method of auction”, emerged in the 2010s to accommodate mortgage buyers.
In a traditional auction, contracts exchange on the fall of the hammer. The buyer pays a 10% deposit on the day and completes within 28 days. This format is used by Allsop, Savills, Strettons, Barnard Marcus, and most commercial auction houses.
In a modern auction, the winning bidder secures the right to buy by paying a non-refundable reservation fee. Exchange happens within 28 days and completion within a further 28 days. This format is dominant at iamsold and SDL Property Auctions, which partner with high street estate agents to list conditional lots.
Timeline: From listing to completion (with comparison table)
Traditional and modern auctions follow different timelines. The table below summarises the key differences.
| Stage | Traditional (Unconditional) | Modern (Conditional) |
|---|---|---|
| Catalogue released | 3 to 4 weeks before auction | Listed continuously online |
| Legal pack available | 2 to 3 weeks before auction | From listing date |
| Viewings | Scheduled open houses | Usually by appointment |
| Bidding format | In-room, livestream, or timed online | Timed online only |
| Contract exchange | On the fall of the hammer | Within 28 days of winning |
| Deposit | 10% on the day | 4.5% reservation fee (min ~£6,000) |
| Completion deadline | 28 days from exchange | 56 days from winning |
| Finance required | Cash or bridging typical | Standard mortgage possible |
| Legally binding | Instantly | On exchange |
Modern auctions are more forgiving for buyers who need mortgage time, but the reservation fee is non-refundable if the deal falls through. Traditional auctions are cheaper in fees but demand financial readiness before the hammer.
What happens before the auction
Pre-auction preparation is where most serious buyers spend their time. You should complete four tasks in the two to three weeks before the auction closes.
First, review the catalogue and shortlist lots. Check recent sold prices on HM Land Registry Price Paid Data at landregistry.data.gov.uk to benchmark the guide price against comparable sales. Second, visit the property. Auction houses schedule group viewings, typically two to three slots over 10 days.
Third, download the legal pack from the auction house website. This contains the Title Register, searches, and Special Conditions of Sale. Instruct a solicitor to review it. Expect to pay £300 to £600 for a solicitor review. Fourth, arrange finance. Cash buyers need proof of funds. Mortgage or bridging buyers need a decision in principle.
Finally, register to bid. Auction houses require ID, proof of address, and a card authorisation or refundable bidder deposit (usually £3,000 to £5,000). Online bidders must register at least 24 to 48 hours before the lot closes.
How the bidding process works
Bidding is tightly choreographed. In an in-room auction, the auctioneer opens each lot by announcing the guide price and inviting an opening bid. Bids typically rise in £1,000, £2,500, or £5,000 increments. The auctioneer signals when the reserve has been met with phrases like “I am selling” or “on the market”.
In a timed online auction, each lot has a set closing time. Placing a bid within the final minute usually extends the timer by 60 or 90 seconds to prevent sniping. The auction ends when no further bids are placed within the extension window.
Livestream auctions combine both formats. The auctioneer broadcasts from a studio while online bidders and in-room buyers compete live. This hybrid format is now standard at Allsop, Savills, and Barnard Marcus.
Always bid with a maximum figure in mind. Set it based on your deal analysis, not the adrenaline of the room. Platforms like Estately.uk track live bid activity across major UK auction houses, letting you follow colour coded bid patterns in real time.
What happens when you win
When the hammer falls in a traditional auction, three things happen immediately. The contract is legally exchanged. You pay the 10% deposit. You sign a memorandum of sale on behalf of yourself and the seller.
In a modern conditional auction, winning the timed lot triggers a 28 day exchange window. You pay the reservation fee within hours via the auction platform. You then instruct your solicitor, finalise your mortgage, and exchange contracts before the deadline.
Either way, you are expected to have your solicitor details ready. Auction houses will not release the memorandum of sale until they have the buyer’s solicitor contact information.
After the hammer falls: the legal process
Post auction, the auction house sends the signed contract and memorandum to both solicitors. Your solicitor requisitions the file and prepares for completion. In a traditional sale, you have 28 days, which is tight.
Completion day works like any other conveyancing completion. Your solicitor transfers the remaining 90% of the purchase price, plus Stamp Duty Land Tax (SDLT), plus legal fees. SDLT on additional dwellings currently carries a 5% surcharge on top of standard bands. Use the HMRC SDLT calculator at gov.uk to estimate your bill before bidding.
Once funds clear, the keys are released. The Land Registry is notified and the title is transferred into your name. This typically takes six to eight weeks post completion.
Common questions buyers have at each stage
First time auction buyers usually have the same concerns. What if the survey reveals problems after exchange? You bear that risk entirely. Survey or self survey the property before bidding, or walk away.
What if the mortgage valuation comes in low? In a traditional auction, the shortfall is yours to cover. In a modern auction, you may be able to renegotiate with the seller, but the reservation fee is still lost if you walk.
What about tenanted properties? Read the Special Conditions and any assured shorthold or regulated tenancy paperwork in the legal pack. Regulated tenants can suppress vacant possession value by 25 to 40 percent.
Frequently Asked Questions
See the FAQs at the end of this guide for answers to the questions buyers ask most often about the auction process.
For a broader overview of UK property auctions, see UK Property Auctions: The Complete 2026 Guide. For a deep dive on finding hidden value at auction, see Property Auction Arbitrage.