Error code
R01 — Missing Health Service Number (HSN)
Out-of-province number missing
This out-of-province (Reciprocal Medical Billing) claim had no health service number for the patient.
What to do: Add the registration number from the patient's home-province health card, check the other patient fields, and resubmit.
- Code
- R01
- Description
- Missing Health Service Number (HSN)
Explanation
Updated October 26, 2026
R01 means a Reciprocal Medical Billing (out-of-province) claim had no health service number. Add the patient's home-province number and resubmit.
What it means
Error R01 means the Reciprocal Medical Billing (RMB) claim was rejected because the patient's health service number (HSN) was missing.
Reciprocal Medical Billing (RMB) is how Ontario physicians bill OHIP for insured services to patients covered by another Canadian province's or territory's health plan, except Quebec. An RMB claim uses payment program RMB and carries the patient's out-of-province registration details instead of an Ontario health number.
Common causes
- The patient's out-of-province registration number was never recorded
- The number was entered in the wrong field, or dropped when the claim was built
How to fix it
- Get the registration number from the patient's provincial or territorial health card.
- Check the RMB patient fields against the patient's card: the two-letter province code, the registration number from the home province, date of birth, surname, first name and sex. The payment program must be RMB and the payee must be P (pay provider).
- Resubmit the corrected claim within three months of the service date if you can. If that window has passed but the claim was first submitted on time, use the Ministry's stale-dated resubmission process.
Don't resubmit if
- If the patient's out-of-province card has an expiry date and has expired, don't submit an RMB claim. The patient is responsible for the charges (Claims submission manual).
How APEX handles it
APEX reads your error reports and remittance advice from MCEDT and lists claims rejected with this code in its Correction Centre for you to correct and resubmit. See how APEX works · Pricing