1. Yes, effectively on their Mum's death, her half share would be divided equally between the three sons with the result that in equity, irrespective of the fact Thomas's name is on the deeds, that your father and Neil would each own a one-sixth share in the property with Thomas owning the remaining two thirds. What your father should do here is to extract letters of administration to your mother's estate so as to handle the transfer of her share into the three sons name. In this way it will be clear what the situation is and Thomas will be forced to deal with the real ownership issue. Accordingly, I would advise your father to speak to a solicitor about administering his Mum's estate and about taking out probate to her estate. Alternatively if Thomas will agree, he could enter negotiations about Thomas buying out your father and Neil's share in the house.