Looking through the prior posts around this topic, I found this one A005 - Named Clinician Issue but it ended in a “lets have a call” 
Below I go into (likely far too much detail) - but in short, we identify our service, we create the referral, we retrieve the available appointment slots (not scoped to a clinician) , we select one appointment and when trying to book it, we receive a “clinician’ (null) does not match the slot” which is confusing as the call to A015 does not include any clinician info.
Does anyone have any tips on what am I missing in this process?
Thanks in advance
Hayward.
The longer / more detailed description follows ..
We have created an referral for a directly bookable service. UBRN in INT environment is “000049829549” ← incase this helps.
Getting the available slots for the given service via the minimal call to A015 where appointment type matches the service search and referral creation.
{
“_count”: “100”,
“_include”: null,
“appointmentType”: “TWO_WEEK_WAIT”,
“page”: “1”,
“schedule.actor:HealthcareService”: “6710874”,
“status”: “free”
}
We then get a list of available appointment slots. One of which is :
{ "resource": { "id": "28216437", "identifier": [ { "system": "``https://fhir.nhs.uk/Id/alternative-slot``", "value": "2605310003961100010120" } ], "schedule": { "reference": "Schedule/6710874-100258351989" }, "status": "free", "start": "2026-05-31T10:00:00", "end": "2026-05-31T10:19:00", "actor": null }, "search": { "mode": "match" } },
However, when we try to book the slot using:
{
“description”: “e-Referral Appointment”,
“end”: “2026-05-31T10:19:00+00:00”,
“id”: “appointment”,
“incomingReferral”: [
{
“reference”: “ReferralRequest/000049829549/_history/4”
}
],
“language”: “en”,
“meta”: {
“profile”: [
“``https://fhir.nhs.uk/STU3/StructureDefinition/eRS-Appointment-1”``,
“``https://fhir.hl7.org.uk/STU3/StructureDefinition/CareConnect-Appointment-1”
]
},
“participant”: [
{
“actor”: {
“identifier”: {
“system”: “``http://fhir.nhs.net/Id/ers-service”``,
“value”: “6710874”
}
},
“status”: “accepted”
},
{
“actor”: {
“identifier”: {
“system”: “``http://fhir.nhs.net/Id/nhs-number”``,
“value”: “9729883815”
}
},
“status”: “accepted”
}
],
“resourceType”: “Appointment”,
“slot”: [
{
“reference”: “Slot/28216437”
}
],
“start”: “2026-05-31T10:00:00+00:00”,
“status”: “booked”
}
We receive an error stating that the clinician (null) does not match the slot. But there is no mention of a clinician in the appointment slot retrieval.
{
“ErsDiagnosticText”: “‘clinician’ (null) does not match the slot”,
“ErsIssueCodes”: [
{
“Code”: “INAPPROPRIATE_VALUE”,
“Display”: “Inappropriate value”
}
],
“ErsOriginalHttpCode”: 422,
“ErsStatusCode”: “UnprocessableEntity”,
“Payloads”: [
“Payload to send: {resourceType:Appointment,id:appointment,meta:{profile:[``https://fhir.nhs.uk/STU3/StructureDefinition/eRS-Appointment-1,https://fhir.hl7.org.uk/STU3/StructureDefinition/CareConnect-Appointment-1``]},language:en,status:booked,description:e-Referral Appointment,start:2026-05-31T10:00:0000:00,end:2026-05-31T10:19:0000:00,slot:[{reference:Slot/28216437}],incomingReferral:[{reference:ReferralRequest/000049829549/_history/4}],participant:[{actor:{identifier:{system:``http://fhir.nhs.net/Id/ers-service,value:6710874``}},status:accepted},{actor:{identifier:{system:``http://fhir.nhs.net/Id/nhs-number,value:9729883815``}},status:accepted}]}”,
“Payload to received: ReferralNexus.Services.Models.ERSErrorResponse”
]
}
