The terms that most often cause confusion, in plain language.
Auction terms
Guide price — An indication of where bidding opens and roughly where the seller’s expectation sits. Not a valuation and not a forecast of the sale price.
Reserve — The lowest price the seller will accept. Confidential, and usually at or above the guide.
Lot — A single property offered at auction.
Increment — The minimum step between bids, set by the lot’s current value.
Extension — Additional time added when a bid lands close to the end, so late bids can be answered.
Sold subject to contract — The bidding has produced a buyer, but contracts have not yet exchanged.
Money
Reservation fee — Paid by the buyer on the Modern Method of Auction to secure exclusivity. Non-refundable and additional to the purchase price.
Reservation deposit — Where the sum taken at close counts toward the purchase price rather than being a fee. The lot states which applies.
Deposit — On traditional auction, the sum paid at exchange, forming part of the purchase price.
Legal
Buyer Information Pack — The legal pack: title, searches and special conditions, published before bidding.
Special conditions of sale — Terms departing from the standard conditions, often including costs passed to the buyer.
Exchange — The point at which the sale becomes legally binding on both sides.
Completion — Transfer of ownership and the balance of the money.
Overage — A clause entitling the seller to a further payment if the buyer later realises additional value, typically through planning permission.