APA amendment allowed before finalization if it does not alter the nature of the original application; additional fee may apply. An APA applicant may request a written amendment before finalization; DGIT (International Taxation) may permit amendments for unilateral APAs and competent authorities may permit amendments for bilateral or multilateral APAs, provided the amendment does not alter the nature of the original application. The applicant must pay any additional fee, and a request to convert a unilateral application into a bilateral or multilateral APA is not considered an alteration of the original application.