The first step to do after finding your ideal home, in order to get to the final act, is to make a purchase offer, in writing, addressed to the seller and to pay a small deposit, usually by cheque, made payable to the owner, or by bank transfer.
The real estate agent will fill out the form, which is written by the estate agency, inserting all the conditions relating to the sale. It contains precise promises made to the seller, by the potential buyer, including data and conditions for the purchase, such as: address and description of the property, cadastral data, price, terms and conditions of payment, the date for the preliminary signing, the date for the notarial deed, and the date by when the seller must accept the offer.
If the seller accepts your conditions (written acceptance) both parties will be bound to complete the sale as established in the offer and the seller will cash your cheque or bank transfer, usually equal to 5% of the agreed price, which will become the deposit.
In case of non-acceptance the seller, through the real estate agent, will return the amount paid. From that moment you are free to walk away the deal or you can reformulate a new proposal with the same procedure as the previous one.