HOW AUCTION HOUSE GUARANTEES AND ENHANCED HAMMER DEALS WORK: A GUIDE FOR ART SELLERS
Doug Woodham | May 2026
Auction houses competing for valuable consignments may offer sellers enhanced hammer deals, guarantees, and other favorable terms. Here is how these arrangements work, how their economics differ, and what sellers should consider when comparing offers.
Owners of valuable art are often surprised by how aggressively auction houses will compete for a consignment. One house may offer to rebate part of the buyer’s premium. Another may guarantee the seller a minimum price. A third may combine a guarantee with an aggressive upside-sharing formula. The differences can be worth hundreds of thousands, or even millions, of dollars.
This article focuses on two of the more complex financial arrangements that can arise when valuable art is consigned at auction. For a broader guide to selling art, including gallery resales, private sales, auction-house selection, estimates and reserves, and the sale of an entire collection, see Selling Valuable Art: What Every Collector Needs to Know.
This guide explains the economics of these arrangements. It begins with how auction houses make money, since their sources of compensation shape what they can offer consignors. It then examines basic and tiered enhanced hammer deals, including how rebates are calculated. The guide next turns to guarantees, explaining how risk and upside are divided and how different auction outcomes affect the consignor, the auction house, and, where applicable, a third-party guarantor. It concludes by comparing enhanced hammer deals and guarantees and identifying the factors sellers should consider when evaluating competing proposals.
The guide draws on my experience advising collectors on major auction consignments, as well as my years as President of Christie’s Americas. Individual proposals and contracts vary, so the examples used below are intended to illuminate the economics of these arrangements rather than prescribe terms for a particular sale.
How Do Auction Houses Make Money on Art Sales?
Auction houses have three principal sources of revenue from art sales: the buyer’s premium, commissions and expenses charged to the consignor, and, in guaranteed consignments, a share of the upside. Understanding where that money comes from is important because it determines how much flexibility an auction house has when competing for valuable property.
What Is the Buyer’s Premium at an Art Auction?
The buyer’s premium is an additional charge paid by the successful bidder on top of the hammer price, which is the final bid price announced by the auctioneer. Premium rates are tiered, with different percentages applied to different portions of the hammer price.
For example, as of May 2026, Christie’s charges buyers 27 percent on the first $1.5 million of the hammer price, 22 percent on the portion from $1,500,001 through $8,000,000, and 15 percent on the portion above $8 million. If a work sells for a hammer price of $2 million, the buyer pays a premium of $515,000, bringing the total purchase price to $2.515 million, before applicable taxes.
For sellers of valuable art, the buyer’s premium matters as it gives the auction house revenue it can sometimes share with the consignor. Enhanced hammer deals are built around this idea.
How Do Seller Commissions Work at Art Auctions?
An auction house may charge the consignor a seller’s commission, usually calculated as a percentage of the hammer price. Unlike publicly posted buyer’s-premium rates, seller’s commissions are individually negotiated and can vary according to the value of the property, the sale category, and the level of competition for the consignment. Other expenses, including shipping, restoration, framing, or photography, may also be charged to the consignor.
For valuable artworks, however, seller’s commissions and these other expenses are typically waived as auction houses compete for the consignment. A zero-percent deal means the consignor pays no seller’s commission. An all-in deal means the auction house also absorbs any supplementary expenses.
How Do Auction Houses Make Money from Guarantees?
An auction house may guarantee the consignor a minimum amount when a work is offered for sale. In return for assuming the risk that the work sells below that amount or fails to sell, the house typically receives a negotiated share of any proceeds above the guarantee.
The auction house may retain that risk itself or share it with a third-party guarantor. The economics can become more complicated when a third party is involved, but the basic principle is the same: someone assumes downside risk in return for financial compensation if the sale performs well.
These three forms of compensation give auction houses flexibility when competing for valuable property. They can waive seller-side charges, share part of the buyer’s premium through an enhanced hammer deal, or assume downside risk through a guarantee in exchange for a portion of the upside. The next sections examine how these last two deal structures work.
What is an Enhanced Hammer Deal?
An enhanced hammer deal builds on a zero-percent, all-in consignment agreement by giving the consignor something more: a share of the buyer’s premium paid by the successful bidder. The seller therefore receives not only the hammer price, but also an additional payment funded from the auction house’s buy-side revenue.
Enhanced hammer deals are expressed as a percentage of the hammer price. A seller might receive 102 percent, 105 percent, or 112 percent, depending on the terms negotiated. A “105 deal,” for example, means the consignor receives 105 percent of the hammer price. If a painting sells for a hammer price of $2 million, the consignor receives $2.1 million: the $2 million hammer price plus a $100,000 enhanced-hammer payment.
The more valuable and commercially desirable the property, the more of its buyer’s-premium revenue an auction house may be willing to share to secure the consignment.
How Is the Buyer’s Premium Shared in an Enhanced Hammer Deal?
Using Christie’s buyer’s-premium schedule as of May 2026, the buyer of a work with a $2 million hammer price would pay a premium of $515,000, bringing the total purchase price to $2.515 million before taxes or other charges. Under a 105 enhanced hammer deal, the auction house pays $100,000 of that buyer’s-premium revenue to the consignor. The economics would be:
| Amount | |
|---|---|
| Hammer price | $2,000,000 |
| Buyer’s premium | $515,000 |
| Total paid by buyer | $2,515,000 |
| Enhanced-hammer payment to consignor | $100,000 |
| Total received by consignor | $2,100,000 |
| Buyer’s premium retained by auction house | $415,000 |
After paying the enhanced hammer, the auction house retains $415,000, equal to 16.5 percent of the buyer’s total purchase price.
How Are Enhanced Hammer Deals Negotiated?
There is no standard enhanced-hammer percentage or fixed value threshold at which one becomes available. The terms depend on the estimated value and commercial appeal of the property, including its quality, condition, and freshness to the market. The size of the consignment can also matter, as an auction house may be willing to offer more favorable terms to win a collection than it would offer for a single work.
Competitive conditions between auction houses are also important. One firm may be trying to gain market share and therefore offer unusually aggressive terms. Another may already have enough high-value property for an upcoming sale and feel less pressure to compete. A third may be short of an important work shortly before an auction deadline and become willing to improve its offer. The enhanced hammer available for the same artwork can therefore vary significantly from one auction house to another and from one sale season to the next.
For that reason, a consignor is unlikely to know the best available terms by negotiating with only one firm. The strongest offers generally emerge when several auction houses are invited to inspect the property and submit proposals. This allows the consignor to compare not only estimates and marketing plans, but also how much of the buyer’s premium each firm is willing to share.
How Does a Tiered Enhanced Hammer Deal Work?
A tiered enhanced hammer deal changes how the buyer’s premium is shared once the hammer price exceeds an agreed threshold.
Suppose a painting carries an estimate of $10 million to $15 million. The parties might agree that the consignor will receive 110 percent of the hammer price up to $15 million, but only 108 percent on any amount above that threshold. In effect, the auction house retains an additional 2 percent of the excess. If the painting sells for $18 million, the reduced enhanced-hammer rate applies to the $3 million above $15 million. The auction house therefore retains an additional $60,000 that otherwise would have gone to the consignor.
This structure is intended to align incentives by giving the auction house a greater financial reward for achieving an exceptional result. The consignor should nevertheless examine the threshold carefully. This deal structure makes the most sense when it rewards performance meaningfully above expectations, rather than allowing the auction house to earn additional compensation for reaching a price it already believed the work was likely to achieve.
What is an Auction Guarantee?
Collectors are sometimes reluctant to sell at auction because the outcome is uncertain. A work might fail to sell, leaving it “burned” in the eyes of the market. Or the consignor may worry that the estimates are too low and the work could sell for less than what they think it is worth. Yet an auction also exposes the work to a broad pool of potential buyers, creating the possibility of a strong result. Sellers are therefore often caught between the opportunity for upside and desire for certainty.
An auction guarantee addresses this tension by promising the consignor a minimum amount regardless of the sale’s outcome. The auction house may provide the guarantee itself, known as a house guarantee, or transfer some or all of the risk to a collector, gallery, or investor through a third-party guarantee. Guarantees have long been used at the top end of the art market, although there is no universal minimum value at which they become available.
How Does a Basic Auction Guarantee Work?
Suppose a collector wants to sell a painting but wants certainty that she will receive at least $2 million. After negotiating with several auction houses, she signs a consignment agreement containing the following terms:
A $2 million guarantee. This is the minimum amount the auction house promises to pay the consignor. She receives $2 million even if the work sells for less or fails to sell. The auction house has therefore assumed the downside risk of the sale.
An 80/20 upside split. If the painting sells for more than $2 million, the amount above the guarantee is divided between the consignor and the auction house. In this example, the consignor receives 80 percent of the upside, while the auction house retains the remaining 20 percent.
A guarantee changes the economics for both parties. Under an enhanced hammer agreement, the auction house has no capital at risk if the work performs poorly. With a guarantee, it may lose money if bidding falls short of the guaranteed amount. The trade-off for the seller is straightforward: the guarantee provides greater certainty, but the seller gives up a portion of the upside if the work performs well. Guarantee arrangements also rarely include an enhanced hammer component, so the seller gives up that potential source of proceeds in exchange for certainty.
What Happens When a Work Sells Above or Below the Guarantee?
Consider how three different hammer prices affect the consignor and the auction house.
The painting sells for $2.5 million. The consignor receives $2.4 million: the $2 million guarantee plus 80 percent of the $500,000 upside. Using Christie’s buyer’s premium schedule, the auction house collects a premium of $625,000. Ignoring expenses and assuming it has retained all of the guarantee risk, the auction house earns $725,000 from the transaction: the $625,000 buyer’s premium plus its $100,000 share of the upside. The consignor receives more than the guarantee, while the auction house is rewarded for assuming the risk.
The painting sells for $2 million. The consignor receives the guaranteed $2 million but no additional proceeds. The auction house collects $515,000 in buyer’s premium.
The painting sells for $1.5 million. The auction house loses money on the transaction. The consignor still receives the guaranteed $2 million, while the buyer pays the $1.5 million hammer price plus a buyer’s premium of $405,000, for a total of $1.905 million. The auction house must contribute $95,000 to make up the difference from its own funds, before accounting for any other sale-related expenses.
The final scenario shows how a guarantee shifts downside risk from the consignor to the auction house. It also helps highlight why an auction house may sometimes prefer to accept a hammer price below the guarantee rather than have the work fail to sell. Had the auctioneer rejected the $1.5 million bid, the auction house would still have owed the consignor $2 million while being forced to take ownership of the painting, that could take months or years to eventually sell.
Enhanced Hammer or Auction Guarantee: Which Is Better for the Seller?
Neither structure is inherently better. An enhanced hammer generally offers greater upside if the work sells well, while a guarantee protects the seller if bidding is weak or the work fails to sell. The better choice depends on the terms offered, the seller’s expectations about demand, and the value the seller places on certainty.
Consider the two examples used earlier in this guide: a 105 enhanced hammer deal and a $2 million guarantee with an 80/20 upside split. The seller’s proceeds under several possible outcomes would be:
| Hammer price | Seller receives with 105 enhanced hammer | Seller receives with $2 million guarantee | Better result for seller |
|---|---|---|---|
| $1.5 million | $1.575 million | $2.0 million | Guarantee by $425,000 |
| $2.0 million | $2.1 million | $2.0 million | Enhanced hammer by $100,000 |
| $2.5 million | $2.625 million | $2.4 million | Enhanced hammer by $225,000 |
| $3.0 million | $3.15 million | $2.8 million | Enhanced hammer by $350,000 |
In this example, the guarantee produces the better result when the hammer price falls materially below $2 million. At a hammer price of approximately $1.9 million, the two structures produce the same proceeds for the seller. Above that point, the enhanced hammer produces more. The difference widens as the hammer price rises. Under the enhanced hammer deal, the seller receives 105 percent of each additional dollar of hammer price. For a guarantee deal, once the threshold has been exceeded, the seller receives only 80 percent of each additional dollar because the auction house retains the remaining 20 percent as compensation for assuming the downside risk.
The basic trade-off can be summarized as follows:
| Issue | Enhanced hammer | Guarantee |
|---|---|---|
| Minimum proceeds assured? | No | Yes |
| Who bears the downside risk? | Consignor | Auction house or 3rd party guarantor |
| Does the seller share in the buyer’s premium? | Yes | Generally not |
| Does the seller surrender part of the upside? | No | Yes |
| Is auction-house capital at risk? | No | Yes |
| Generally better suited to | A seller confident in demand | A seller prioritizing certainty |
Based on my work with clients, a guarantee may be especially valuable when a seller faces an estate-tax deadline, needs liquidity, or cannot tolerate the risk of a failed sale. An enhanced hammer may be preferable when demand appears strong, the seller can accept uncertainty, and the guarantee requires giving up too much of the potential upside.
In any event, sellers should compare the proceeds each deal structure would produce across a range of plausible auction outcomes. A seemingly generous guarantee can prove expensive if the work performs well, while an aggressive enhanced hammer can be costly if the sale disappoints. The best structure is the one whose balance of certainty and upside best fits the seller’s circumstances.
Considering the Sale of Valuable Art?
Art Fiduciary Advisors helps collectors and families solicit competing auction proposals, compare guarantees and enhanced hammer terms, negotiate improved economics, and select the sale strategy best aligned with their objectives. Learn more about Doug Woodham’s advisory services here.
About Doug Woodham
Doug Woodham is Managing Partner of Art Fiduciary Advisors, a New York–based firm that advises collectors and families on financial decisions involving art. He previously served as President of Christie’s Americas and as a partner at McKinsey & Company, where he advised asset- and wealth-management clients in the United States, Europe, and Asia. An economist with a Ph.D. from the University of Michigan, he is the author of Jean-Michel Basquiat: The Making of an Icon and Art Collecting Today: Market Insights for Everyone Passionate About Art.
