Systems and methods that transport Charging Data Records (CDRs) using GTP′ for offline charging. One embodiment comprises a Charging Data Function (CDF) that communicates with a Charging Gateway Function (CGF) of an offline charging system using GTP′. The CDF assembles a GTP′ request for a transaction, assigns a sequence number for the transaction, and assigns a timestamp to the sequence number. The CDF inserts the sequence number in a GTP′ header of the GTP′ request, inserts the timestamp assigned to the sequence number in the GTP′ header of the GTP′ request, and sends the GTP′ request to the CGF.