when we looked at a house on auction we put a sealed bid in and sent it in. we also had to send in a deposit for 10% of the value of the house, in our case the house was at a asking price of 65,000 so we had to send 6,500 in, on the day of the auction we had a phone call and someone bid on our behalf in the saleroom, they were in london we were in newcastle, we had a cut off price of 80k and were not allowed to go over this without prior written agreement, so when we got outbid we lost the house and couldn't do anything to stop it as we reached our limit, sadly we lost by 3k. Hope this helps.x