I would also add that there needs to be proof of source of income for the purchase and/or mortage payments, with full employment background checks.

I have heard stories of houses purchased by a single person claiming “housekeeper” or “artist” as their income, mysteriously able to make huge mortgage payments or purchasing mansions outright. Turns out they were, of course, getting off-shore funds from a spouse or relative, and the job they claimed was just a sham.