Over the last couple of weeks we have been experiencing intermittent time outs when making requests to various eRS FHIR API endpoints. We are using CIS 2 and unattended access. Most of them have been when requesting an attachment download. A request, > 3 hours later, to download the same attachment will be successful. The latest failure details are as follows:
2026-06-23 14:16:30.004 +01:00 [DBG] A042:Retrieve Attachment ‘Digital weight management NEL CEG (R.rtf’ for UBRN 000481******. xCorrelationId:f821b7df-bff1-446b-b4e1-ae9fe31f1d8b.2026-06-23 14:16:30.006 +01:00 [INF] Sending HTTP request GET https://api.service.nhs.uk/referrals/FHIR/R4/Binary/44f8c698-35c6-4f06-b49c-*2026-06-23 14:18:10.030 +01:00 [ERR] The request was canceled due to the configured HttpClient.Timeout of 100 seconds elapsing.
We don’t log the 307 response or the Location header so we can’t tell if its the 307 that’s causing the timeout.
Are you able to investigate the request with the xCorrelationId shown above? We are trying to find out if its an issue at the eRS end or our own.