Quote from bigarrow:
That is almost exactly what my banker told me last week.
The lender is writing the mortgage on the property, not on the buyer. Thus a mortgage can't be approved without a property to appraise, and a buyer to evaluate.
Many things in that equation can change between final "Approval" and closing to kill the deal. Conditions of the buyer can change, conditions of the property value can change, conditions in the financial markets can change, conditions at the lender itself can change, and even the sellers conditions can change prior to the moment of closing that may cause them to walk away.
I have seen many deals die right at the closing table. Documents are delayed and buyers/sellers get into a pissing match, interest rates weren't locked in and changed overnight, the house was not measured correctlty and overlooked in the appraisal, the wife just filed for divorce because she wouldn't commit to a long term mortgage, a final-walkthru uncovers flooding in a basement, a lender learns that the buyer was just laid off or he BLEW OUT HIS TRADING ACCOUNT AND DOWN PAYMENT, zoning around the area was just changed and altered an appraisal, the seller just lost a transfer and needs to stay in his home, etc. etc. etc. Happens every day.
Nothing is certain until the funds are deposited in the sellers account, and the keys are in the buyers hands.