Legal Question in Real Estate Law in California

Technically that is not legal, and with a commercial property owner or management company like for big apartment complexes, you could expect a credit report ding for it. With what seems to be an amateur landlord who is going out of business, however, it is unlikely you will face any repercussions, particularly since he will lose standing to do anything about it once the foreclosure occurs. If I were in your shoes I would give notice today for June 30 and tell the landlord to take the last month rent out of the deposit and see what happens. On the up side, if the foreclosure goes forward as scheduled, the new owner will be liable to you for your deposit jointly with your current landlord. So if he gives you a 3-day notice because he doesn't want to take the rent out of the deposit, and you have to pay, you will have some recourse for your deposit.

There is sometimes a difference between what's strictly "legal" (i.e., in accordance with the law of lease agreements) and what's practical in the real world. Your risk is quite low if you simply give a written 30-day noticefor June 30th on or before May 31st. Keep the rent money handy (unspent) and see what happens. After all, your landlord has an obligation to provide you with "quiet enjoyment" during the lease term, and that means freedom from legal issues of all kinds associated with his ownership of the property and his right to be your landlord, and by allowing a foreclosure he is the first to breach an implied term of the rental agreement.