Auction platform rules compared
How seven auction platforms, from eBay to classic cars, handle seller and house bidding, late bids, maximum bids and retractions, from each platform’s own terms and help pages. Rules change, so the sources are listed at the end with the date we checked them.
Updated
Checked October 9–10, 2026. This compares published rules, not how well each platform enforces them, and it says nothing about any seller. Where a platform’s terms don’t answer a question, the table says so.
Can the seller, the house or staff bid?
The question that matters most for shill bidding. Some auction houses allow bids on the seller’s behalf below a reserve, and say so in their terms; consumer marketplaces ban seller bidding outright.
| Platform | Rule |
|---|---|
| eBay | No. Bidding that pushes up a price is banned for the seller and anyone connected to them, including family, friends, roommates, employees and online connections. |
| eBay Live | No, under the same eBay policy. The eBay Live policy also bans fake bidding or engagement to drive up prices. eBay Live listings can’t have reserves. |
| Whatnot | No. Bids from a seller, or anyone related to them (employees, family, household, friends, online connections), that inflate a price are banned, from the same account or a separate one. |
| Goldin | Goldin may place bids below the reserve on the seller’s behalf. Officers, directors and employees of Goldin and its affiliates, including eBay, may bid as long as they don’t know the reserve. Bidders confirm their bidding isn’t part of a collusive agreement. |
| Fanatics Collect | No. Shill bidding is banned, consignors can’t bid on their own items, and employees (and their households) can’t bid at all. Auctions have no reserves. |
| Heritage Auctions | Yes, within limits set out in its terms. Consignors may bid on their own lots, and their bids are treated as made in good faith. Heritage may place protective bids for a consignor, and Heritage, its affiliates and employees may bid. |
| Bring a Trailer | No. Sellers and anyone associated with them or the vehicle may not bid on the listing. Reserves are allowed, and a seller can lower the reserve while the auction runs. |
What happens to late bids?
Whether a bid near the end adds time. Extensions make last-second sniping less useful.
| Platform | Rule |
|---|---|
| eBay | Auctions end at a fixed time. eBay is testing extended bidding in some categories. |
| eBay Live | The seller can turn on extra time: a bid in the last 5 seconds adds 5 seconds. eBay Live auctions are usually under 2 minutes. |
| Whatnot | Standard timers add a few seconds per bid. Sudden Death timers add none. Many auctions end in 30 seconds or less. |
| Goldin | Each lot with a new bid extends by a set number of minutes, set per auction. Opening bids must be in by 9 pm ET on closing day. |
| Fanatics Collect | Extended bidding starts at 7 pm PT on closing night. Weekly lots close one by one after a quiet period that shrinks to 1 minute; in Premier auctions, a bid on any item extends the whole auction, and increments halve in the 1-minute windows. |
| Heritage Auctions | In Extended Bidding auctions, people who have already bid on a lot can keep bidding until a set time passes with no bids. The window varies by category. |
| Bring a Trailer | The auction ends only once two full minutes pass after the highest bid. Auctions usually run 7 days. |
Does it bid for you up to a maximum?
Automatic bidding keeps your maximum private and raises your bid only as far as needed.
| Platform | Rule |
|---|---|
| eBay | Yes. Every bid is a maximum. |
| eBay Live | Yes. eBay bids for you in increments up to your limit. |
| Whatnot | Yes. Max Bid is on by default for custom bids, and pre-bids work the same way. |
| Goldin | Yes. A maximum bid is executed for you in standard increments. |
| Fanatics Collect | Yes. Every bid is a maximum. Fanatics says it can’t view bidders’ maximums, and it bans sniping services. |
| Heritage Auctions | Yes. Your current bid is the lower of your maximum or one increment above the next bidder. |
| Bring a Trailer | No. Your bid goes in at the amount you enter. |
Can you take a bid back?
A platform that lets bidders retract freely is easier to game, for example with bid shielding.
| Platform | Rule |
|---|---|
| eBay | Only in a few situations, such as typing the wrong amount, and within the 12-hour rule. Retractions are public. |
| eBay Live | No. eBay Live bids are final. |
| Whatnot | No. If you win, you can ask the seller to cancel within 24 hours, and they can say no. |
| Goldin | No. All bids are final and binding; Goldin decides how to handle bidding mistakes. |
| Fanatics Collect | No, except with Fanatics’ prior approval, which it calls exceedingly rare. It reviews retractions over a rolling 12 months. |
| Heritage Auctions | Only with a written request, stating a reason, that Heritage receives and acknowledges. |
| Bring a Trailer | No. BaT says it doesn’t cancel bids. |
What can other bidders see?
What you can check about the people bidding against you.
| Platform | Rule |
|---|---|
| eBay | Masked names (a***b) with feedback scores, a bid history for about 90 days, and each bidder’s 30-day summary. |
| eBay Live | The current high bid and the bidder’s username, during the auction. |
| Whatnot | The current highest bid. Maximum bids are private. |
| Goldin | Not stated in its terms. Reserves are confidential; from 10 pm ET the day before close, a lot shows when its reserve isn’t met. |
| Fanatics Collect | Not stated. Maximum bids are private. |
| Heritage Auctions | Not stated. Maximum bids are unseen by other bidders and consignors. |
| Bring a Trailer | Usernames, and each member’s full account history on their public profile. |
Where to report suspected shill bidding
The route each platform gives, if it gives one.
| Platform | Rule |
|---|---|
| eBay | eBay says you don’t need to report shill bidding, because its systems look for it. Sellers can report buyers who abuse retractions. |
| eBay Live | Report content or activity that breaks the eBay Live policy. |
| Whatnot | Report from the person’s profile icon in the show, or email trustandsafety@whatnot.com. |
| Goldin | No specific route found. General support: support@goldin.co. |
| Fanatics Collect | The “report a violation” button on listings, or trust@fanaticscollect.com. |
| Heritage Auctions | The “Feedback or Report a Problem” link. Texas auction concerns can also go to the Texas Department of Licensing and Regulation. |
| Bring a Trailer | No specific route found. General contact: mail@bringatrailer.com. |
Bidding to the reserve isn’t the same as shill bidding
In US auction law, a seller bidding on their own lot is a problem when it wasn’t announced: if the right to bid wasn’t reserved, a buyer can void the sale or take the item at the last good-faith bid (UCC section 2-328). Traditional auction houses often reserve that right in their terms, usually to protect a reserve price. Consumer marketplaces like eBay and Whatnot don’t allow it at all.
What this means for you: on a platform that allows bids on the seller’s behalf below the reserve, someone bidding against you early on may not be another collector. Set your maximum by what the item is worth to you, and read the platform’s terms before you bid. See what is shill bidding?
Sources
- eBay: Shill bidding policy, Canceling bids and managing bidders, Retracting a bid.
- eBay Live: eBay Live FAQ, Shopping on eBay Live, eBay Live policy, Selling on eBay Live.
- Whatnot: Bid on an item during a show, Community Guidelines, Report a profile or listing.
- Goldin: User Agreement.
- Fanatics Collect: Premier Auction, Weekly Auction, Help centre and Marketplace Terms.
- Heritage Auctions: Terms and Conditions of Auction, Auction types. Heritage’s site blocked our checks, so its terms were read from an archived copy (revision dated April 8, 2025, archived July 2026). Check the live page before relying on them.
- Bring a Trailer: How BaT works, FAQ, Terms of use.
Spotted a rule that has changed? Tell us through the review form and we’ll update the table.
Common questions
Is it shill bidding when an auction house bids up to the reserve?
Not when it’s disclosed and allowed by the rules of that auction. US auction law treats seller bidding as a problem when the right to do it wasn’t announced; several auction houses reserve that right in their terms. Consumer marketplaces such as eBay and Whatnot ban seller bidding outright.
Which platforms ban shill bidding?
eBay, eBay Live, Whatnot, Fanatics Collect and Bring a Trailer ban the seller and people connected to them from bidding to push up the price. Goldin and Heritage allow some bidding on the seller’s behalf, as set out in their terms.
Which platforms let you retract a bid?
eBay allows retractions in a few situations, and Heritage on a written, acknowledged request. eBay Live, Whatnot, Goldin, Fanatics Collect (except with prior approval) and Bring a Trailer don’t.
Watching an auction?
Capture its bid history and see which signs are present, with the evidence for each.