It is important to have your conveyancer examine the contract before auction, to make sure that everything is in order. It is also important to have your finance arranged with unconditional approval. Also make sure all necessary building inspection have been completed. You cannot complain about any of these issues after you purchase at an auction. Talk to the estate agent about auction registration and procedures. If you are successful, you must then sign the contract and pay a deposit. A personal cheque is acceptable. Note there is no cooling off period for an auction purchase.