The difference between the number shown in CLM01 of the 837P and the one displayed on the CMS1500 is due to the fact that CLM01 uses an internal identifier generated by the system for the electronic submission of the claim, while the CMS1500 shows the patient’s EMR number as an internal clinical reference. This results in two different numbers: one serves the technical purpose required for claim submission, and the other maintains the patient’s usual identification.