Guide price vs reserve price at auction: what do they actually mean?
The auction guide price is the first number a buyer sees when browsing property lots — and it is also one of the most misunderstood. First-time auction buyers frequently assume it represents the price the property will sell for, or that it is some form of professional valuation. It is neither of those things.
Understanding the difference between the guide price, the reserve price, and the final hammer price at auction is one of the most important things you can do before you set foot in an auction room or register to bid online. Each of these figures plays a different role, they are governed by different rules, and confusing them can lead to significant financial mistakes.
This guide explains each term clearly, covers the regulatory rules that govern how they must relate to each other, and sets realistic expectations about what the guide price actually tells you when you are preparing your bid.
What is an auction guide price?
An auction guide price is a publicly advertised figure — or range of figures — that gives prospective buyers an indication of the level at which bidding is expected to start and where the seller’s minimum expectations roughly lie. It is set by the auctioneer, usually in consultation with the seller, and it is designed as a marketing tool first and foremost. The guide price is not a valuation. It does not represent a professional assessment of what the property is worth in the open market. It is a number calculated to generate interest — ideally enough interest to drive competitive bidding that pushes the final price well above where it started. In practice, auction properties regularly sell for 15% to 25% above their guide price when demand is strong. A guide price can be shown in two ways:- A single figure: for example, £175,000. Where a single figure is used, the auction reserve price must be no more than 10% above that figure, meaning the reserve can be set up to £192,500 in this example.
- A price range: for example, £160,000–£175,000. Where a range is used, the auction reserve price must fall within that range — in this example, somewhere between £160,000 and £175,000.
What is an auction reserve price?
The auction reserve price is the absolute minimum amount the seller has authorised the auctioneer to accept. It is confidential — known only to the seller and the auctioneer — and it is legally binding. The auctioneer cannot sell the property for less than the reserve, regardless of how many bids have been received or how much pressure there is to get the lot away.
The reserve is the seller’s safety net. It ensures they cannot be forced into accepting a price far below their expectations simply because the room was quiet on the day. At the same time, because the reserve must be set within the parameters defined by the guide price, buyers have a meaningful indication of where the reserve is likely to sit even though they cannot know the exact figure.
The reserve price can also be changed before the auction begins — but it must be finalised and agreed before bidding starts. Once bidding is underway, the reserve cannot be altered mid-lot. If the highest bid does not reach the reserve, the property is not sold at auction, though the seller may choose to negotiate with the highest bidder immediately afterwards.
One important nuance: some properties are offered at auction without any reserve price. These “no reserve” lots will sell to the highest bidder regardless of the final figure. Properties sold without a reserve often attract intense early bidding because buyers recognise the opportunity to purchase below any floor. These lots are less common and usually involve unusual circumstances — an estate needing quick disposal, for example, or a clearance of assets at any price.
What is the hammer price at auction?
The hammer price at auction is the final winning bid — the figure at which the auctioneer’s gavel falls and the legally binding contract comes into existence. At the moment the hammer falls, the buyer and seller are committed. There is no cooling-off period, no opportunity to renegotiate, and no way to withdraw without significant financial penalty.
The hammer price is the figure that matters most, but it is not the same as the total cost of purchasing the property. The hammer price at auction is the base from which additional costs are added — and those costs can be substantial. They typically include:
- Buyer’s premium: a fee charged by the auction house on top of the hammer price, usually 1.5% to 3% plus VAT
- Administration fee: a fixed charge payable on the day, sometimes called a “buyer’s fee” or “administration charge”, often in the range of £500 to £2,000 plus VAT
- Solicitor’s legal fees: for the conveyancing work required to complete the purchase
- Stamp Duty Land Tax: calculated on the hammer price, not the guide price, and must be budgeted for accordingly
- Survey costs: if a survey was commissioned before bidding
None of these are included in the hammer price itself. Failing to budget for them is one of the most common and costly errors made by buyers who are new to auctions. A full breakdown of what you should expect to pay on top of the hammer price is set out in our guide to all the fees involved when buying a property at auction.
Unsure what the guide price really means?
A pre-auction legal pack review can help you look beyond the guide price, understand the true cost behind the hammer price, and spot legal risks before you commit. Request a legal pack review before bidding
How the three prices relate to each other
The guide price, the reserve price, and the hammer price at auction sit in a structured relationship, though only part of that relationship is visible to buyers.
The guide price is public. The reserve is private but governed by rules that constrain how far it can sit from the guide. The hammer price is the outcome — determined entirely by bidder competition on the day. These three figures can end up close together or very far apart, depending on the level of interest the property generates.
A practical example helps illustrate the relationship. A property is listed with a single-figure guide price of £200,000. Under ASA rules, the auction reserve price can be no more than 10% above the guide, meaning the reserve is somewhere between £200,000 and £220,000. If strong buyer interest pushes competitive bidding, the hammer price might be £265,000 — well above both the guide and the reserve. If interest is modest and bidding only just crosses the reserve, the hammer price might be £215,000 — barely above where the seller was prepared to sell.
This is why the guide price should never be treated as a target or a ceiling. It is a starting point for your research, not a reliable forecast of what the property will sell for.
How guide prices are set — and how accurate they tend to be
Auctioneers set guide prices using a combination of factors that a professional surveyor or estate agent would recognise: comparable sales in the area, the condition and size of the property, any legal or structural complications, the potential for improvement or development, and current market demand.
In practice, guide prices are deliberately set conservatively. Auctioneers know that a low guide price attracts more registered bidders, more registered bidders create more competition in the room, and more competition drives the hammer price higher. The interests of the seller and the auctioneer are aligned in wanting competitive bidding — and the guide price is calibrated to encourage exactly that.
Guide prices are not formal valuations. They are not produced by independent RICS-qualified surveyors, they are not required to reflect open market value, and they can diverge significantly from what a lender’s surveyor would value the property at if you were financing the purchase with a mortgage. If you are borrowing to buy at auction, the lender will require their own valuation — and if that comes in below the hammer price, you will need to cover the shortfall from your own resources.
The accuracy of guide prices varies considerably between auction houses. Some maintain a reputation for conservative, reliable pricing that reflects genuine market expectations. Others set deliberately low guides to generate interest, knowing that the reserve sits comfortably above. Reviewing the auction house’s recent sold results — comparing guide prices to actual hammer prices — gives you a useful sense of how reliable their pricing is.
What happens if the reserve price is not met?
If bidding in the room — or online — does not reach the auction reserve price, the auctioneer cannot sell the property. The lot is described as “passed in” or “withdrawn” and the property leaves the auction unsold.
This does not necessarily mean the transaction ends at that point. In many cases, the auctioneer will approach the highest bidder immediately after the lot closes and ask whether they wish to make a post-auction offer directly to the seller. The seller can then accept, reject, or counter-negotiate. If agreement is reached after the auction, the same legal terms and conditions that would have applied in the room typically apply to the post-auction sale — meaning exchange is swift and the usual 28-day completion deadline often still stands.
For buyers who were outpriced in the room, a passed-in property represents an opportunity to negotiate in a calmer environment. The seller’s motivation has not changed, and the fact that the property has already failed to sell once may give the buyer some leverage. Being the highest bidder when a lot is passed in is a useful position to be in, even if it was not the outcome you intended.
Getting legal advice before you buy a house at auction
Having a specialist solicitor review the auction legal pack before you bid is not optional — it is the most important step you can take to protect yourself. A specialist auction pack review will identify any special conditions that increase your costs, flag title issues that affect value, and give you a clear picture of the total financial commitment before you raise your hand.
AuctionSolicitor.co.uk provides fixed-fee, fast-turnaround auction pack reviews and full conveyancing for buyers across the UK. With auction deadlines being strict and legally binding, instructing the right solicitor before — not after — you buy a house at auction makes all the difference.
Common mistakes buyers make with guide and reserve prices
Several misunderstandings about auction pricing consistently cost buyers money. Knowing what they are before you bid is the most effective way to avoid them.
Treating the guide price as the expected sale price is the most frequent error. Buyers build a budget based on the guide, arrive at the auction, and find themselves outbid early in the process because competitive interest has driven the price well above where they expected it to settle. Setting a budget based on the guide price alone — without allowing for the 15% to 25% premium that many lots attract — leaves you unprepared.
Assuming the guide price is a valuation is equally dangerous. A property listed with a guide price of £120,000 may have a structural defect, title issue, or onerous special condition that a professional valuation would flag and that explains why the guide is set where it is. The guide price reflects the auctioneer’s assessment of what will generate bidding — not what the property is worth to a careful buyer with full information.
Ignoring the fees on top of the hammer price compounds both errors. If your maximum budget is £150,000 and a property sells at £148,000, you may still find yourself unable to complete once the buyer’s premium, administration fee, and legal costs are added. Always calculate your total budget, not just what you are prepared to bid.
Experienced auction buyers and the legal pitfalls that catch unprepared bidders are covered in our guide to the most common mistakes made when buying property at auction — worth reading before you attend your first event.
Why the legal pack matters more than the guide price
However important the pricing terminology is, the guide price tells you nothing about the legal condition of the property you are bidding on. The real information about what you are buying — and the real risks — is contained in the legal pack.
The legal pack is a set of documents prepared by the seller’s solicitor and made available to prospective buyers before the auction. It contains the title register, special conditions of sale, any existing searches, tenancy agreements if the property is let, and details of any legal charges, restrictions, or covenants affecting the property. The hammer price is only meaningful if you understand what you are contracting to purchase at that price.
Special conditions of sale are of particular importance. These are contractual terms that modify or override the standard auction conditions. They can impose additional costs on the buyer — contribution to the seller’s legal fees, payment of an administration charge, or responsibility for specific search costs — and they become legally binding the moment the hammer falls. A property with an attractive auction guide price may carry special conditions that make it significantly more expensive in total.
Having a solicitor review the legal pack before you bid is the standard practice of every informed auction buyer. Our auction pack review service provides a detailed assessment of everything in the pack — the title, the special conditions, the searches, and any risks that are not immediately obvious — so that the guide price and the reserve price are not the only things informing your decision.
Preparing to bid: using guide prices effectively
The auction guide price is most useful as a filter and a starting point — not as a figure to bid against directly. Here is how to use it effectively as part of your preparation:
- Use the guide to shortlist properties: if a guide price is clearly outside your maximum budget even allowing for a 20% to 25% premium, eliminate it early. If it fits comfortably within your budget at that uplift, it warrants further research.
- Research comparable sales: look at what similar properties in the same area have actually sold for — both at auction and through estate agents. This gives you a realistic sense of where the hammer price is likely to settle, independent of what the guide price suggests.
- Review the legal pack before the auction: the guide price means nothing if the legal pack reveals a problem that materially affects the property’s value or usability. Do this before you register to bid, not after.
- Set your maximum and stick to it: decide in advance the absolute most you are prepared to pay — including all fees on top of the hammer price — and commit to it. Auction rooms are designed to create momentum and urgency. Knowing your number before you go in is your most important protection against overpaying.
Everything you need to do before bidding at a property auction — from viewing the property and commissioning searches to arranging your finance and reviewing the legal pack — is covered in our detailed guide to what to do before you bid at auction.
Know the price — and know what is behind it
The auction guide price, the auction reserve price, and the hammer price at auction are three distinct concepts that every buyer needs to understand before they bid. The guide is a marketing figure with a regulatory relationship to the reserve. The reserve is the seller’s confidential floor. The hammer price is the outcome — and it is the figure to which all other costs are added.
But pricing is only part of what you need to know before committing to an auction purchase. The legal position of the property — what you are actually contracting to buy when the hammer falls — is contained in the legal pack, and that deserves at least as much attention as the guide price.
At Auction Solicitor, we review legal packs for buyers across England and Wales, providing clear, specialist advice on what is in the pack, what it means for your purchase, and what risks you need to understand before you raise your paddle. If you have a legal pack you would like reviewed ahead of an auction, contact our team to get a fast, fixed-fee assessment.
Don’t bid based on the guide price alone
The guide price is only a starting point — not a valuation, not a final price, and not the full cost of buying at auction. Before you raise your paddle, have the auction legal pack reviewed so you understand the reserve price risks, special conditions, hidden buyer costs, and your real maximum bid.
