A payer is sending the submitter ID of the clearinghouse in the REF*PQ rather than an identification for the payee. Per the definition of this loop this is a loop for payee information, not submitter. Please confirm if the payer can continue to send clearinghouse submitter in loop 1000B, or if this is correct.
The 1000B loop is used to identify the payee. The REF - Payee Additional Identificaiton is only required when identification of the payee is dependent upon an identification number beyond that supplied in the N1 segment. Using this segment to identify an entity other than the payee is not compliant with the usage rules of the loop or segment.