Potential buyers in the room bid on your property.
The person in the room who bids the highest wins the auction.
Once the gavel goes down, the person who bids is legally commited to make the purchase.
The buyer will have to pay a 10% deposit on the auction day.
The contracts between buyer and seller are also exchanged on the auction day.
Generally completion should happen within 28 days (most auction houses are flexible on this).
The buyers deposit is lost should they fail to complete the sale.
The buyer may also be forced to pay a fee if they fail to complete on the sale.