This answer will depend on whether you are a tenant or the previous owner. Further it could depend on where the property is located.
If you are a tenant with a valid lease, or proof of rent payment, the new owners will take the property subject to the terms of your lease. They may offer you "cash for keys" to leave early if they feel it's in their best interest. If the home is in a city (eg. Los Angeles, Santa Monica, West Hollywood) with rent control laws, the amount they can offer you to leave and how quickly they require you to leave will still be subject to those laws.
If you are the homeowner who lost the home to foreclosure, your "clock" will start upon being contacted by the new owner or one of their agents.
If the property was sold to a third party investor at the trustee sale it's likely someone would attempt to contact you either the same day of the sale or within 24 hours. Most investors will either look to keep you as a paying tenant (less likely) or seek to have you move within 30 days or less. You will be given a written notice of your rights as the previous owner, which do not include the right to stay, and asked to leave. Some investors may offer you a financial incentive to move if you leave willingly, in short order, and do not damage the property.
If your home went back to the lender and became an REO you will be contacted by a real estate agent who is hired to sell the house, or a tenant outreach division at the bank. Similarly to the process when an investor buys the home you will be contacted within hours to days after the house changes ownership. The contact will be in writing (likely a posted notice on the front door) explaining the options the bank will allow for tenants and/or prior owners.
As mentioned above, tenants with valid leases and/or in rent control areas are subject to the rights in the lease and/or the rent control laws governing the area where the home is located. Owners will typically be asked to leave and given between 30 and 90 days to vacate the premises on their own volition. Some banks will pay "cash for keys" incentives for a previous owner to leave sooner and to leave the home in good condition, others may not.
These are general guidelines followed by most banks and investors. These time lines also represent situations where the current occupant cooperates with the new owner. In cases where the prior owner does not cooperate or contact the new owner in a timely manner, they will almost always seek to evict the prior owner as soon as possible.
I hope this helps and wish you luck as you move forward.
Allan S. Glass
ASG Real Estate Inc. Â®
149 S. Barrington Ave, Suite #660
Los Angeles . CA 90049
Direct: 213.973.8637 (213.97.FUNDS)
CA License: 01154002