Magicians who wish to join may spend up to two years as an Apprentice before applying for full membership. They need to have known two current members for at least one year and must be at least 18 years old. These two members are then asked to act as sponsors, or referees, on the candidate's application form and propose them as a suitable candidate for membership. Following the receipt and processing of the application, the candidate is invited to an interview with the examinations secretary, usually at the London headquarters. If the candidate proves suitable and sufficiently knowledgeable a performance exam is scheduled or a thesis may be written. The exam takes place in front of a panel of judges, and candidates must demonstrate their skills to members in a rehearsed act.