An ERF or EQ6 rejection indicates that the billing number of the referring physician provided is not currently eligible for referrals. The physician could be inactive (not eligible to practice in Ontario, left the province, retired, or deceased).
Check that you have the correct billing number. Alternatively, you can bill a different service code that does not require a referring physician. If the claim does not require a referring physician, you can simply remove the referring physician information and resubmit.