Understanding buyer’s premiums, seller’s commission and hammer prices

When buying or selling coins and banknotes at auction, understanding the fees is part of understanding the result.

The final bid is not necessarily the amount a collector pays or the amount a consignor receives.

For buyers, the important figure is the total cost of acquiring a lot. For sellers, it is the net amount received from the sale of their coins, banknotes or collection.

At Copeland Roberts, our buyer’s premium is 22% including GST. We are also offering 0% seller’s commission on all consignments formally accepted on or before 31 December 2026, even if the items are auctioned after that date. Acceptance remains subject to suitability for auction.

Our fee structure provides a useful example of how a numismatic auction transaction works and why both sides of the transaction matter.

What is the hammer price?

The hammer price is the final accepted bid for a lot, before the buyer’s premium and any other buyer charges are added.

For example, if a 1923 halfpenny sells at auction for $1,500, that is the hammer price. The auction house then adds its buyer’s premium to that amount.

What is a buyer’s premium?

The buyer’s premium, sometimes called buyer’s commission, is a percentage charged to the successful bidder in addition to the hammer price.

At Copeland Roberts, our 22% buyer’s premium includes GST. A $1,000 winning bid therefore attracts a $220 premium, making the subtotal $1,220 before applicable buyer charges.

The calculation is:

Hammer price × 1.22 = purchase subtotal including buyer’s premium.

Collectors should include this premium when setting their bidding limits. If your budget for a banknote is $2,000 including our buyer’s premium, approximately $1,639 is available for the hammer price.

Allow separately for shipping and insurance.

What is the seller's commission?

Seller’s commission, also called vendor’s commission, is the fee charged to the consignor for selling their material. It is usually calculated as a percentage of the hammer price and deducted from the sale proceeds.

For example, if a collection achieves a $20,000 hammer total and the agreed seller’s commission is 10% including GST, the commission is $2,000. The consignor receives $18,000 before any other agreed seller deductions.

At 0% seller’s commission, the same $20,000 hammer total produces $20,000 for the consignor, assuming no exceptional charges apply under the consignment terms. Buyer shipping and insurance are paid separately by the purchaser and are not deducted from the consignor’s proceeds.

An auction house may charge both a buyer’s premium and a seller’s commission on the same sale.

How buyer’s premium and seller’s commission affect net proceeds

Where bidders have a fixed total budget, a higher buyer’s premium leaves less available for the hammer price.

Suppose successful bidders collectively spend $150,000 on a collection, including buyer’s premiums but excluding other buyer charges.

The table below shows how different fee structures divide that fixed amount between hammer prices and commissions. All commission percentages include GST where applicable; figures are rounded to the nearest dollar.

The comparison assumes identical total buyer spending and no other seller deductions. These examples illustrate fee calculations only and do not predict the result any auction house would achieve.

For consignors, the useful point is that both the buyer’s premium and seller’s commission deserve consideration.

Choosing a numismatic auction house involves more than fees

A favourable fee structure matters, but so does the work behind the sale.

For coins and banknotes, accurate identification and grading help bidders understand what they are buying.

Clear photography allows collectors to assess surfaces, strike, toning and other details.

Descriptions should identify relevant varieties and disclose issues such as cleaning, repairs or damage where detected.

Lotting also matters. A scarce coin may warrant an individual lot and detailed description, while an accumulation of common material may be more practical to offer as a group.

Estimates, reserves and promotion should suit the material and its likely buyers.

When comparing auction houses, consider:

• The quality of their descriptions and photographs.

• How they will group, estimate and promote your collection.

• Their ability to reach relevant collectors and encourage bidding competition.

• The complete buyer and seller fee structure.

• Settlement terms.

For consignors, the key financial consideration is the likely net amount received after commission and any applicable seller charges.

Other charges to check

Buyers comparing auction houses should check shipping, insurance, payment surcharges and any additional platform charges before bidding. These costs, where applicable, sit outside the hammer price and buyer’s premium.

Sellers comparing auction houses should ask whether any separate lotting, photography, marketing or other fees apply. These are questions to ask across the industry, not a list of charges imposed by every auction house. At Copeland Roberts, we charge no routine photography, lotting or marketing fees. Exceptional charges may apply under our consignment terms.

Buying and selling through Copeland Roberts

If you are considering selling coins, banknotes or a collection, send photographs and a brief description to contact@copelandroberts.com for an initial assessment. Our team can discuss suitability for auction, expected values and the consignment process.