| Code | Display |
| 10001 | Handling Specification Error | |
| 10002 | Infrastructure Level Response Value - Processing Error | |
| 10003 | Business Level Response Value - Processing Error | |
| 10004 | Message Definition Value - Processing Error | |
| 10005 | Message Definition Version Value - Processing Error | |
| 10007 | Sender Reference Value - Processing Error | |
| 10008 | Handling Specification Business Rule Error | |
| 10009 | Unreadable message received | |
| 10010 | Recipient Type - Processing Error | |
| 20001 | Unrecognised Recipient Person | |
| 20002 | Unrecognised Recipient Organisation | |
| 20003 | Unrecognised Sender | |
| 20004 | Non-Approved file type received as an attachment | |
| 20005 | Unsupported file type received as an attachment | |
| 20006 | ITK header validation failure | |
| 20007 | Duplicate Message received | |
| 20008 | Duplicate Document received | |
| 20009 | Payload validation failure | |
| 20010 | Unrecognised Payload Recipient Organisation | |
| 20011 | Unrecognised Payload Recipient Person | |
| 20012 | Unauthorised Sender | |
| 20013 | Success | |
| 20014 | Unable to Process Replacement Document | |
| 20015 | Message too large | |
| 30001 | Patient known here. (e.g. Patient is registered here) | |
| 30002 | Patient not known here. (aka 'patient record not present in system') | |
| 30003 | Patient no longer at this clinical setting | |
| 30004 | Patient known here and recently deceased (i.e. patient record current in GP practice system at time of patient’s death and deduction subsequently occurred for this reason) | |
