Proxy bidding explained: let guests set a maximum and enjoy the evening

Proxy bidding, also called maximum bidding or autobid, lets a guest tell the system the most they are willing to pay for a lot. The system then bids on their behalf, one increment at a time, only as high as it needs to go, and never past the number they set. It is how the large online marketplaces have worked for twenty-five years. At a charity evening it does something slightly different and more useful: it lets somebody commit their real number while they are still at the table with a glass in their hand, instead of you dragging it out of them at 22:40 when they have stopped paying attention.

The mechanics, with numbers

A dinner voucher opens at €60, with increments of €10. Anna decides it is worth €120 to her and sets that as her maximum. Here is what happens, step by step.

• Anna sets €120. The screen shows €70 — one increment above the opening bid, not €120.
• Ben bids €80 from his phone. Anna's proxy answers €90 within a second.
• Ben goes to €100. Anna's proxy answers €110.
• Ben tries €130. Anna's proxy stops at €120 and Anna gets an outbid message.

Two things in that sequence surprise people. The first is that Anna never showed €120 until she had to. If Ben had given up at €80, Anna would have won at €90 and paid €90 — her maximum is a ceiling, not a price. The second is the speed: the counter-bid lands before Ben has put his phone down, which is a large part of what makes a room believe the auction is alive.

What it does to your total

The gain is not mysterious. A guest bidding by hand bids the next step, then waits to see whether it hurts. A guest setting a maximum answers a different question — what is this actually worth to me — and answers it honestly, in private, with nobody at the table watching. Those two numbers are rarely the same. A mid-sized lot that would drift to €150 on manual bidding will often be walked to €280 or €320 by a pair of committed maximums, without either bidder touching their phone again.

It also fixes the thing that quietly costs a silent catalogue the most: dead lots. Twenty lots in ninety minutes means each one gets a few seconds of anyone's attention. A lot that opened at a third of its value and took one bid tends to stay there — not because nobody wanted it, but because nobody wanted it enough to keep checking their screen through the speeches.

A lot that looked dead and was not

At a school auction last spring the treasurer spent most of the evening watching Lot 12 — a week in a donated cottage, opening bid €150 — sit at €180 while the coffee went round. She had written it off and was drafting the apologetic line she would use on the donor. At 21:52 the silent close ran and the lot landed at €430. Two guests had set maximums of €400 and €430 at around half past eight and then gone back to their dinner. The screen had shown €180 for an hour because €180 was all it needed to show.

The apology was not needed. What was needed, and what she had not done, was warn the donor beforehand that a quiet lot and a cheap lot are not the same thing.

What guests get wrong

• Round numbers. Everybody picks €100, €150, €250. Two identical maximums produce a tie, decided by who set theirs first, which feels arbitrary to whoever loses. Say from the stage: choose an odd number. €155 beats €150 every time.
• Setting a maximum at the current bid. The system refuses it, the guest reads the refusal as a fault in the tool, and a fair share of them stop there rather than try again one step higher.
• Assuming the maximum is public. It is not, and people bid considerably more freely once somebody tells them so. Nobody sees Anna's €120 except Anna.
• Forgetting they set one. A guest who put €300 on three lots at eight o'clock and won all three has a bill they did not brace for. A confirmation per maximum, plus a visible list of their own active maximums, prevents a bad conversation at the payment desk.

What organisers get wrong

The commonest mistake is switching proxies on and leaving the increments where they were. With €2 increments on a lot standing at €40, two maximums of €200 will generate eighty steps and eighty notifications inside a minute. Set increments at roughly five to ten per cent of the current level, or step them up as the price rises: €5 under €100, €10 up to €250, €25 above that.

The second mistake is not explaining it. A guest who bids €90 by hand and is beaten within a second, three times running, does not think proxy bidding. They think the thing is rigged, and they say so to their table. Thirty seconds from the front of the room prevents it.

The third is using proxies on the headline lots in the live block. Don't. The auctioneer, the raised hands, the pause before the third bid — that is the show, and a silent machine does not improve it. Keep maximums for the catalogue and for anyone bidding from home. The organiser's guide sets out which lots belong in which block.

Ties, and the other edge cases

• Equal maximums. The earlier one wins, in almost every system. Know that rule before somebody asks at the desk, and announce it rather than defend it afterwards.
• Raising your own maximum while leading. It should not move the visible price. If your system bumps the current bid when the leading bidder raises their own ceiling, that is worth discovering the week before, not at 21:00.
• Withdrawing a maximum. Decide the policy in advance. Most organisers allow a guest to lower a maximum only as far as the current bid and never below it, which is the same rule an auctioneer applies to a hand already in the air.
• Reserves. If a lot carries a reserve, a proxy sitting below it must not display as a winning bid. Otherwise somebody goes home believing they have won a boat trip they have not won.
• Remote bidders. A guest watching from home cannot refresh through the speeches and cannot read the room. A maximum is the only way they compete on equal terms. If you run a hybrid evening, proxies are not optional.

One line from the stage

"You can set a maximum, and we bid for you until somebody passes it. You only pay one step above the next person — not your maximum, unless the race really goes that far."

Say it once at the start, once when the silent catalogue opens, and put it on the table card. Clubs where the same forty people return every year can say it less each season; the pages for clubs cover what changes once an audience knows the format. In a first-time room, over-explaining costs nothing.

Where it fits

Silent lots, hybrid evenings, and any audience of busy parents who came for the dinner. Which is most audiences. Set a maximum against yourself on a dummy lot first, because a bidding flow nobody understands is the one problem you cannot fix once the doors are open. A rehearsal run costs nothing, and the help pages cover the awkward cases: the guest who wants their maximum taken off, or two identical ceilings on the lot everybody wanted.

Proxy bidding runs on every silent lot in auctiontool.ai by default; what the tool costs is on the pricing page.