How to Buy at an Auction Without Overpaying
Published 2026-10-02 · Buying Antiques · Antique Partner
Quick answer: The hammer price is not the price. Buyer's premium runs 10 to 18 percent, online bidding adds more, and tax comes after that. How to work out your real maximum bid before you raise a hand.
Buying Antiques
How to Buy at an Auction Without Overpaying
By Nicolas · October 2, 2026 · 9 min read
Almost everybody who bids at their first auction pays more than they meant to, and it is usually not because they got carried away. It is because the number the auctioneer shouts is not the number on the invoice.
We have written about
what you net when you consign
. This is the same arithmetic seen from the other side of the room, and it is the part nobody explains before you register.
Everything that gets added after the hammer
Charge
Typical
Notes
Buyer's premium
10% to 18%
Set by each house, and added to the hammer price always. Regional rooms sit in this band; Christie's and Sotheby's run tiered rates reaching 25 percent on the first tranche.
Online surcharge
A few points more
Bidding through a live platform rather than in the room usually costs extra.
Sales tax
Your local rate
Charged on the hammer plus the premium, not on the hammer alone.
Packing and shipping
Varies wildly
Often outsourced to a third party. Ask before you bid on anything heavy or fragile.
Work backwards from what you will spend
This is the habit that fixes the whole problem. Do not decide what you will bid.
Decide what you are willing to pay in total, then work backwards to find the bid that produces it.
At an 18 percent premium, a $1,000 budget is an $847 bid. At 20 percent it is $833. Add sales tax and it comes down again. Most people do the opposite: they set $1,000 as the bid, win at $1,000, and open an invoice for $1,180 plus tax.
Write the number down before the lot comes up. Not a rough idea, the actual figure. An auction is designed to make you decide quickly in a room full of people doing the same thing, and the only defence that reliably works is having settled it in advance, in writing, when nobody was watching.
Go to the preview, and assume the catalogue is optimistic
Almost everything sells as seen, with no returns. The preview is the only chance to find out what you are actually bidding on, and it is free.
Open drawers, turn things over, look at joints and backboards, check for replaced hardware and later feet. Take the piece to a window if you can. Condition reports are written by people with a lot of lots to describe and an interest in selling them, so "some wear consistent with age" covers a wide range of sins.
If you genuinely cannot attend, ask for extra photographs and a written condition report by email. A good house will send them. A house that will not is telling you something.
Estimates, reserves and the bidding itself
The estimate is a marketing instrument, not a valuation. It is set to attract bidders, which often means pitching it slightly low. The reserve is the confidential figure below which the lot will not sell, and it usually sits at or under the low estimate.
Two things worth knowing in the room.
Bid increments are the auctioneer's to set
, and a jump bid can end a contest that would otherwise creep upward. And an absentee or left bid, where the house bids on your behalf up to your maximum, is the single best tool for anybody who does not trust themselves in the moment. The house bids only as far as it needs to, so a left bid frequently wins under your limit.
Removal is your problem, and it has a deadline
Most houses give you a short window to collect, often a few days, and charge storage after it. Nobody helps you load. If you have bought a wardrobe, you need a van, a second pair of hands and a plan, on their schedule rather than yours.
This is the most common way a good buy turns into a bad one. Work out collection before you bid, especially at a country sale two hours from home.
The short version
Find the premium before you register. Assume 10 to 18 percent at a regional house, more again online, and up to 25 percent at a major one. Set a total budget and divide back to a bid. Go to the preview and look underneath. Treat estimates as advertising. Leave an absentee bid if the room gets to you. And know how the thing gets home before the hammer falls.
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