There are circumstances in collecting and processing cellular therapy products for further manufacture where more than one donation may need to be collected to deliver a given therapy. A new ISBT 128 Standard for the Chain of Identity (CoI) Identifier, developed based on requirements developed collaboratively with the Standards Coordinating Body, was published in December 2022. This new ISBT 128 data structure provides a standardized, globally unique identifier that can be used to link these donations together. This session will describe the hybrid (split) label format for labeling collection products for cell therapy manufacturing, the structure of the ISBT 128 Chain of Identity Identifier, the maintenance of the chain of custody, and how to become a CoI Identifier issuer. The session will also leverage experience from a cell therapy manufacturer’s journey to establish a chain of identity identifier and overcome bottlenecks in implementing strategies to maintain the chain of custody. An interactive discussion will delve into establishing an agreement between the entities involved in the collection for a given therapy regarding the scope of the therapy to be associated with a CoI Identifier and defining who is responsible for allocating the CoI Identifier that will be used throughout the lifecycle of the biological material, and when the CoI Identifier will be allocated.