What is the question. Is it, can I close the sale without probate- answer is no because without probate the seller has no title and you will not be able to register. Is it can I sign contracts without probate- answer is yes, but put a time limit on getting the probate that you are comfortable with, perhaps with an option to extend if you are happy to do so. Contracts will have a condition that closing will take place only after probate granted and that if probate is not granted within certain time limit that you can pull out. Your solicitor will presumably explain all this to you.