To be a registered trader, interested parties have to refer to the national customs authorities’ procedure for registration to use the ACTS system. Once the registration has been approved, the trader can start to use the ACTS system. For the purpose of ACTS, the person responsible for the transit operation is ‘The Principal’ for ACTS, and maybe the owner of the goods, or more often, the owner’s representative (such as the carrier). Please refer to the quick guide to trader registration and relevant trader registration forms attached below.
For more information on getting registered as a transit trader, please refer the following contact points:
Singapore
ACTS overview for Singapore: https://www.customs.gov.sg/businesses/asean-customs-transit-system/overview
Registration Link for Singapore: https://www.customs.gov.sg/businesses/asean-customs-transit-system/registration-and-acts-declaration
Email: customs_international@customs.gov.sg
Malaysia
Email: ccc@customs.gov.my; myacts@customs.gov.my;
Thailand
Thailand ACTS notification: 
acts_notification_169.2563_be.pdf
ACTS manual for Traders: acts-thai-manual_fortraders.pdf
Email: 109154@customs.go.th; 109163@customs.go.th;
Cambodia
Email: acts@customs.gov.kh;
ACTS Announcement: https://tools.customs.gov.kh/documents/reader/3939/16031945285569693/ACTS-Announcement-KH
ACTS Manual KH: https://api.customs.gov.kh/wp-content/uploads/2015/05/20201016-ACTS-Customs-Procedures-Manual-KH.pdf
ACTS Manual EN: https://api.customs.gov.kh/wp-content/uploads/2021/05/ACTS-English_FA_final.pdf
Lao PDR
Email: clartelaos@gmail.com;
Viet Nam
Email: acts@customs.gov.vn;
Myanmar
Information on Trader Registration of Myanmar will be available soon.
Quick Guide for Registration and Related Documents
quick_guide_for_trader_registration_1_20102020.docx
acts_private_sector_principals_and_transporters_manual_v_31_august_2020.pdf