If I transferred from ATD 2020 to ATD 2021 and cannot attend the new dates, how do I change my registration? Natasha Porter Updated September 28, 2020 19:29 Follow Please contact ATD Customer Care for assistance. Email email@example.com or call +1 703.683.8100 or 800.628.2783. Related articles When can I learn more information about ATD 2021? Can I apply ATD 2020 registration funds to another ATD offering? What are your shipping methods and rates? How do I become a facilitator for ATD education programs?