Auction is the one part of the art market that happens in public. The lots are catalogued, the estimates are printed, the bidding takes place in front of an audience and the results are published within hours. For anyone trying to understand what an artist's work is worth, that openness makes auction records the obvious place to start.
They are a good place to start. They are rarely a good place to stop. An auction result is shaped by fees, by private arrangements made before the sale, and by the way the figures are reported afterwards. Read carelessly, a single result can suggest a market far stronger or weaker than the one that really exists. Read with care, it is some of the best evidence a buyer can have.
THE ESTIMATE IS A FORECAST, NOT A VALUATION
Every lot in a catalogue carries an estimate, expressed as a range: a low figure and a high figure. It is the auction house specialist's view of where bidding is likely to finish, agreed with the seller before the sale.
An estimate is also a marketing decision. Set it too high and bidders stay away. Set it attractively low and more people raise a paddle, which can push the final price well above the range. Auction houses know this, and a modest estimate on a desirable work is a deliberate choice rather than a mistake. Equally, a seller who insists on an ambitious figure may get a high estimate and no buyer.
Two other points are worth knowing. Estimates exclude the buyer's premium and any taxes, so they are not the price you would pay. And when a catalogue says "estimate on request", it usually means the figure is high enough that the house prefers to discuss it privately.
THE RESERVE SITS BENEATH THE ESTIMATE
Most lots carry a reserve, the confidential minimum the seller has agreed to accept. If bidding does not reach it, the lot does not sell. The major houses state in their conditions of sale that the reserve may not be higher than the low estimate, so a lot estimated at £40,000 to £60,000 will not have a reserve above £40,000.
Their conditions also allow the auctioneer to bid on the seller's behalf up to, but not including, the reserve. Those bids are not from any buyer in the room or on the telephone. They simply carry the bidding towards the point at which a sale becomes possible. It is a lawful and disclosed practice, but it does mean that the early momentum of a lot tells you very little about real demand.
HAMMER PRICE AND THE PRICE PAID
The hammer price is the figure at which the auctioneer brings down the gavel. It is not what the buyer pays.
On top of the hammer price, the buyer pays a buyer's premium. At the major international houses this is now charged on a sliding scale. From February 2026, for example, Sotheby's charges 28 per cent of the hammer price up to £1.5 million at its London sales, 22 per cent on the portion between £1.5 million and £6 million, and 15 per cent above that. Christie's and Phillips use similar tiers, with low-band rates of 27 and 29 per cent respectively at the time of writing. Rates change often, so the current figures should always be checked in the sale's own conditions.
Depending on the lot and where the sale takes place, further charges can follow. In the UK, VAT is charged on the buyer's premium, and works brought in from outside the UK for sale may carry import VAT on the hammer price as well, usually at 5 per cent. A royalty for the artist or their estate, known as the Artist's Resale Right, may also apply to works by living artists and those who died within the last 70 years. Catalogues flag these lots with symbols, explained at the back of the catalogue, and they are worth reading before you bid.
WHY THE PUBLISHED PRICE CAN FLATTER THE RESULT
When auction houses publish results, the figure shown is normally the hammer price plus the buyer's premium. That is a fair reflection of what the buyer paid. It becomes misleading when it is set beside the estimate, which was calculated without any premium at all.
Consider a work estimated at £80,000 to £120,000 that is hammered down at £100,000. That is squarely within the estimate. With a premium of 28 per cent, the published price becomes £128,000, which appears to beat the high estimate. Headlines describing results as "above estimate" are often making exactly this comparison. The only like-for-like test is the hammer price against the estimate.
The same arithmetic shows how far apart buyer and seller really are. In that example the buyer pays £128,000, before VAT on the premium. The seller receives £100,000 less their own commission and costs, which are negotiated privately. The gap between what one side pays and the other receives can easily reach a third of the hammer price. Anyone buying with half an eye on a future sale should keep that gap in mind, because a work generally needs to rise substantially in value before a resale at auction returns the original outlay.
UNSOLD LOTS AND WHAT THEY COST
When bidding fails to reach the reserve, the lot is "bought in". The auctioneer will usually close it with a neutral word, and the published results may simply omit it. Many price databases record bought-in lots, but casual searches and press reports rarely mention them.
An unsold lot is still evidence, and often the most important evidence in an artist's record. It tells you that, on that day, no buyer was willing to meet a reserve no higher than the low estimate. A pattern of works failing to sell is a clear sign of weak demand, however impressive the occasional strong result may look.
There is also a lasting cost. A work that has failed publicly is sometimes described in the trade as "burned", and it can be difficult to sell for some time afterwards. Academic research supports this. A study by the economists Alan Beggs and Kathryn Graddy, published in 2008 and based on sales at Christie's and Sotheby's, found that works which had previously failed to sell later achieved significantly lower prices than comparable works that had not.
Two further habits of reporting are worth knowing. Lots withdrawn before the sale are generally left out of the figures altogether. And a bought-in lot may be sold privately in the days after the auction, at which point some sources record it as sold, with no indication that it failed under the hammer.
SELL-THROUGH RATES
Auction houses report how well a sale performed as a sell-through rate, either by lot (the share of lots offered that sold) or by value (the share of the total estimate achieved). Both are useful. Neither is complete. A sale can achieve a high rate by value because of two or three expensive lots while a large share of the cheaper works fail. For an individual artist, the most telling measure is simple: of all the works offered over the past several years, how many sold, and at what level against estimate?
GUARANTEES AND IRREVOCABLE BIDS
Many of the most valuable lots are sold with a guarantee already in place. The auction house, or a third party arranged by it, has promised the seller a minimum price whatever happens on the night. A third party who commits in advance to buy a lot at a fixed level is said to have placed an irrevocable bid.
These arrangements are disclosed in the catalogue with a symbol, and they matter for two reasons. A guaranteed lot is certain to sell, so its appearance in the results says nothing about whether open competition would have produced a buyer. And where a third-party guarantor ends up buying the work, they may receive a financing fee from the auction house, which reduces the effective price they paid below the published figure. A guaranteed lot that sold on a single bid at the guarantee level should be read as a private arrangement completed in public, not as a contested sale.
HOW TO READ A RESULT PROPERLY
■ Compare the hammer price, not the premium-inclusive price, with the estimate. ■ Check the buyer's premium and other charges in that sale's conditions, since they vary by house, location and date. ■ Look for unsold lots by the same artist, and give them as much weight as the successes. ■ Note any guarantee or irrevocable bid symbols, and treat those results with caution. ■ Consider the work itself: its size, date, medium and condition, and whether it is typical of the artist. ■ Look at results over several years and several sales, rather than a single headline figure.
Read this way, auction records turn from a source of headlines into a source of evidence. Seen together, they show not only the best price an artist has achieved, but how deep the demand really runs.
HOW WE CAN HELP
Our researchers monitor results at major and regional auction houses, measured against estimate and including works that failed to sell. That evidence sits at the heart of every Artist Report and Pre-Acquisition Review, and it is set out in plain English, including where the record is thin.