If you are considering signing an unconditional contract please be aware that even if you have a pre-approval in place there still could be issues that arise hindering your ability to purchase the property! For example; in between the time you sign the contract and you proceeding to formal approval a credit default may have been listed against your name. The valuation may have come in short on the property therefore the lender will only loan funds based on the short valuation, leaving you short of funds to purchase the property….or they may decide they do not like the security and will not loan you the funds to purchase the property. You may find through a building an pest inspection that you have major issues with termites, there are many issues that can arise….. In short best to err on the side of caution and be 100% certain your finance has been approved (and you have a satisfactory building and pest inspection) before you go unconditional on a contract.