A buyer's premium is an additional charge, expressed as a percentage of the winning bid, that the buyer pays on top of the hammer price. If you win a lot at $100 and the buyer's premium is 20%, you pay $120 plus any applicable tax. It is the auction house's charge to the buyer for facilitating the sale, and it sits alongside - not instead of - the seller's commission.
How it is calculated
The premium is applied to the hammer price, then tax (where applicable) is calculated on the combined total. The percentage is set by the auction house and disclosed in the terms of sale before bidding opens, so the number is knowable in advance. Buyer's premiums vary by house and by platform, and online sales often carry premiums in the mid-teens to mid-twenties as a percentage - but the only figure that matters is the one printed in that specific sale's terms.
Who it affects
The buyer pays the premium directly, but it shapes bidder behavior for everyone. Experienced bidders factor the premium into their maximum bid - a $500 ceiling at a 20% premium means stopping the hammer bid near $415. Sellers benefit indirectly: the premium is revenue to the house that can offset a lower seller's commission, which is why some auctioneers advertise low or no seller's commission and recover it through the buyer's premium instead.
Where it sits among auction costs
The buyer's premium is one of several line items in an auction's economics, and they are easy to confuse:
| Cost | Who pays it | What it is |
|---|---|---|
| Buyer's premium | Buyer | Percentage added to the hammer price |
| Seller's commission | Seller | Percentage of hammer price kept by the house |
| Online bidding fee | Seller/auctioneer | Platform's cut of sales |
| Cataloging labor | Auctioneer | Cost of preparing the lots |
Two of those line items are frequently muddled, so the distinction is worth stating plainly. According to AuctionFlex 360's published pricing, online bidding carries a fee of 2% of gross auction proceeds - that is a bidding-platform fee, charged for running the sale on the marketplace, not a cataloging charge. According to AuctionWriter's estate auction fees analysis (2025), setup and cataloging labor costs auction houses $25-$45 per hour per crew member for sorting, tagging, and photo upload - that is the cost of preparing lots, a separate thing again. A buyer's premium, a platform bidding fee, and cataloging labor are three different costs paid by different parties. (For the platform-fee side specifically, see does HiBid charge a percentage of sales; for the cataloging-labor side, see how auctioneers charge for lotting and cataloging.)
Where a cataloging tool fits
Worth noting on the tooling side: a cataloging tool is not a marketplace and does not take a percentage of sales. Gavelist charges a flat per-lot cataloging price and takes 0% of auction sales, so it does not touch hammer price or buyer's premium at all.
Frequently asked questions
How much is a typical buyer's premium? It varies by auction house and platform and is disclosed in each sale's terms; online sales commonly land in the mid-teens to mid-twenties percent. Always check the specific sale's terms rather than assuming a standard rate.
Is the buyer's premium the same as the seller's commission? No. The buyer's premium is paid by the buyer on top of the hammer price; the seller's commission is a percentage of the hammer price kept from the seller's proceeds. A single sale can have both.
Does a buyer's premium include cataloging or platform fees? No. It is a separate charge to the buyer. Platform bidding fees (for example, 2% of gross proceeds) and cataloging labor are distinct costs paid by the seller or auctioneer.
Sources
- AuctionFlex 360, "Pricing." auctionflex.com
- AuctionWriter, "Estate Auction Fees Analysis (2025)."