The embodiments herein relate to a method performed by a charging function (125) for handling a subscriber's communication services. The charging function (125) detects that a subscriber's credit account has reached or fallen below a credit threshold when the subscriber has multiple ongoing communication services consuming credit from the credit account. The charging function (125) sends a threshold notification to a UE (101) on which the subscriber has at least one of the multiple ongoing communication services. The charging function (125) determines if a response to the threshold notification has been received with prioritization of one of the multiple ongoing communication services. If a response with prioritization of one communication service has been received, the charging function (125) initiates termination of all ongoing communication services except the prioritized communication service, and provides all available credit to be available for the prioritized communication service.