---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/91305#article
headline: "91305: Sink endpoint rejected the event"
url: https://www.twilio.com/docs/api/errors/91305
inLanguage: en
dateModified: 2026-10-27T17:14:57.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 91305: Sink endpoint rejected the event

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio records this error when Event Streams attempts to deliver an event, but the target sink endpoint rejects the payload with an HTTP 4xx status code.

Because a 4xx response indicates a client-side or configuration error, Twilio does not attempt to retry delivery for these events.

### Possible causes

* Authentication or authorization failures (401 / 403): API keys, credentials, or signing signatures configured on the sink are invalid or expired.
* Invalid endpoint URL (404): The URL path configured on the sink is incorrect or the target route no longer exists.
* Payload or header rejection (400 / 415): The sink endpoint rejected the payload structure, missing parameters, or the `Content-Type` header sent by Twilio.
* WAF or firewall blocking: A Web Application Firewall (WAF), CDN, or bot protection layer blocked the incoming request before it reached your service application.

### Possible solutions

* Inspect sink endpoint's logs to review the full request payload, headers, exact status code, and response body returned to Twilio.
* Verify that any API keys, tokens, or signing secrets configured on the sink match your sink's requirements.
* Confirm that the destination URL and path configured on the sink are active and correctly routed.
* If your endpoint sits behind a WAF or CDN, update firewall and WAF rules to ensure Twilio's IP ranges are allowed.
* Ensure your endpoint is configured to parse the content type (e.g., `application/json`) transmitted by Twilio for this sink type.

### Related errors

* [91300: Event delivery to sink failed](/docs/api/errors/91300)
* [91306: Sink endpoint returned a server error](/docs/api/errors/91306)

#### Additional resources

* [Event Streams overview](/docs/events)
* [Sink resource](/docs/events/event-streams/sink-resource)
* [Subscription resource](/docs/events/event-streams/subscription)