The bid increment is the step size of an auction. If the current bid is $500 and the increment at that level is $50, the next acceptable bid is $550. Increments keep a sale moving at a sensible pace: too small and a $10,000 lot takes a hundred bids to sell; too large and bidders drop out before their true limit because the next step is more than they want to add.
A typical increment table
Increments are set as a table of price bands. The percentages below are the usual target of around 10% of the current price, which is what most collectibles auction houses use.
| Current bid | Increment |
|---|---|
| $0 to $100 | $5 |
| $100 to $200 | $10 |
| $200 to $500 | $25 |
| $500 to $1,000 | $50 |
| $1,000 to $2,000 | $100 |
| $2,000 to $5,000 | $250 |
| $5,000 to $10,000 | $500 |
| $10,000 to $20,000 | $1,000 |
| Above $20,000 | $2,000 or 10% |
Coin and stamp auction houses often use finer steps at the low end because so many lots sell under $100. Fine art sales use coarser steps at the top. The table should be published in the conditions of sale and shown on the bidding screen.
Increments in the room and online
A live auctioneer uses the table as a guide and may take a cut bid, half the increment, to keep two bidders going near the end. Online there is no discretion: the platform enforces the table on every bid, which is one reason the increment table must be set per sale and per category before bidding opens. A live auction platform shows the clerk the current bid, the asking price and the next increment on one screen so that room and internet bidders are always offered the same number.
Increments and maximum bids
Maximum and absentee bids are executed one increment at a time. Two maximum bids of $1,000 and $700 on a $500 lot resolve to a winning bid of $750, one increment over the underbidder, not $1,000. Bidders sometimes leave odd amounts such as $1,010 to beat a round-number rival; a good platform allows the odd amount and uses it only when it is needed.
Setting the table in the software
Circuit stores bid increment tables per sale, enforces them for timed and live online bidding, and executes maximum bids against them. The same table applies whether the bid comes from the room, the phone, the absentee book or the internet.
