14 CFR § 61.35 - Knowledge test: Prerequisites and passing grades.
(a) An applicant for a knowledge test must have:
(1) Received an endorsement, if required by this part, from an authorized instructor certifying that the applicant accomplished the appropriate ground-training or a home-study course required by this part for the certificate or rating sought and is prepared for the knowledge test;
(2) For the knowledge test for an airline transport pilot certificate with an airplane category multiengine class rating, a graduation certificate for the airline transport pilot certification training program specified in § 61.156; and
(3) Proper identification at the time of application that contains the applicant's -
(iii) Date of birth, which shows:
(A) For issuance of certificates other than the ATP certificate with an airplane category multiengine class rating, the applicant meets or will meet the age requirements of this part for the certificate sought before the expiration date of the airman knowledge test report; and
(B) For issuance of an ATP certificate with an airplane category multiengine class rating obtained under the aeronautical experience requirements of § 61.159 or § 61.160, the applicant is at least 18 years of age at the time of the knowledge test;
(iv) If the permanent mailing address is a post office box number, then the applicant must provide a current residential address.
(b) The Administrator shall specify the minimum passing grade for the knowledge test.