Your rights don’t depend on a permit
Yes. This is one of the most important things to understand: renting an illegal unit does not strip you of your tenant rights in California. Landlords sometimes suggest otherwise, but the law generally protects tenants regardless of whether the unit was properly permitted.
As a tenant of an unpermitted unit, you generally still have the right to a habitable home, the right to be evicted only through the proper legal process, protection from illegal "self-help" tactics like lockouts and utility shutoffs, and the return of your security deposit under the usual rules. In many cases, you may have even more leverage, because the landlord chose to rent an unlawful unit and collect rent for it.
A landlord cannot legally use the unit's illegal status as an excuse to ignore repairs, push you out without proper notice, or deny you basic protections.
If a landlord is treating you as if you have no rights because the unit is unpermitted, that is often wrong. A free, confidential review can help you understand the protections you actually have.
This is general information about California tenant rights, not legal advice. Every situation is different.