Regulations for legal interpreters in California differ from those in other states.
Legal Language Services ranks California as a state with moderately regulated legal interpreting requirements.
In general, your legal interpreter must have the appropriate level of certification that meets your language needs. This is especially true if you require a court interpreter.
This does not mean, however, that you should hire a certified interpreter for every situation. Whether or not an interpreter is certified — let alone the level of certification — will have an effect on how much you are charged for legal interpreting services.