Methods and systems for triggerless prepaid short message service (SMS) screening and accounting in a signaling message routing node are disclosed. According to one aspect, the subject matter herein includes a prepaid SMS screening and accounting module. The prepaid SMS screening and accounting module includes a prepaid SMS screening function, where the function is an application program for receiving SMS messages and determining whether the SMS messages are associated with prepaid subscribers. The prepaid SMS screening and accounting module further includes a prepaid SMS accounting function, where the function is an application program co-located with the prepaid SMS screening function for determining, for the prepaid SMS messages associated with prepaid subscribers, whether the subscribers have sufficient credit for delivery of the SMS messages, and, in response, for sending the SMS messages to their intended destinations. At least one processor executes the prepaid SMS screening and accounting functions.