Systems and methods that track Charging Data Functions (CDFs) that handle accounting requests for a session. One embodiment comprises a distributor unit that receives an interim accounting request for a session. The interim accounting request includes a tracking parameter that includes one or more CDF identifiers (ID) indicating one or more CDFs that handled accounting requests for the session. The distributor unit processes the tracking parameter to identify a first CDF ID for a first destination CDF that handled accounting requests for the session. When the first destination CDF is not available to receive the interim accounting request, the distributor unit selects a second destination CDF for the interim accounting request based on a distribution algorithm. The distributor unit adds a second CDF ID for the second destination CDF in the tracking parameter of the interim accounting request, and transmits the interim accounting request to the second destination CDF.