We are seeking a guidance on proper 999 creation in the following case. An incoming 270 transaction has a problem with Subscriber Trace Number, 2000C\TRN02. This transaction is acknowledged back with 999, version 005010X231A1. Since the error occurs within a business unit (Subscriber = Patient), segment CTX “Business Unit Identifier” is expected to be created with a value of Subscriber Trace Number. But since the trace number has a problem, a proper CTX cannot be created as it would create a 999 transaction with invalid syntax (which should not be done). So what is the recommendation in this case? Simply omitting CTX segment in such a case or something else?
The CTX Business Unit Identifier note states, "Required when the error reported in this IK3 loop is within a business unit and the business unit identifier is known by the submitter of the 999. If not required by this implementation guide, do not send." In the case of invalid characters, the submitter of the 999 is unable to use the business unit identifier due to syntax errors and therefore it is considered unknown to the submitter of the 999. As such, the CTX Business Unit Identifier would not be sent based on the situational rule. In the case that the data contains more than 35 characters, the data should be truncated to contain the first 35 characters from the business unit identifier.