As a court interpreter ("sworn and court-certified translator and interpreter") for the English language, I regularly work for courts, government authorities but also private individuals.
If I offer my services as a sworn and court-certified translator and interpreter, this means that I have undergone a quality assurance procedure (selection process) in order to proof of my professional qualifications.
Once you pass the exam, you are included in the list of court interpreters for a limited period of five years. Upon application, your certification can be extended for five additional years at a time if you stil meet the requirements (regular assignments at court, further training, etc.).