---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/45002#article
headline: "45002: Authentication Error"
url: https://www.twilio.com/docs/api/errors/45002
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 45002: Authentication Error

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio returned this error because the request to a protected resource did not include valid authentication credentials. This can happen when credentials are missing, incorrect, expired, or do not have permission to access the requested resource.

### Possible causes

* The request did not include authentication credentials.
* The Account SID, API Key, API Secret, or auth token is incorrect.
* The request used expired or revoked credentials.
* The credentials are valid but do not have access to the requested Flex resource.
* The request sent the wrong authorization header format or malformed credentials.

### Possible solutions

* Confirm that your request includes authentication credentials.
* Verify that you are using the correct Account SID, API Key, API Secret, or auth token for the account and environment you want to access.
* Regenerate or rotate credentials if you suspect they have expired, been revoked, or been exposed.
* Check that the credentials you are using have permission to access the requested Flex resource.
* Review your authorization header and request formatting to make sure credentials are sent correctly.
* If you use API Keys or IAM controls, review your authentication setup and key management configuration.

#### Additional resources

* [Twilio IAM documentation](/docs/iam)
* [Flex documentation](/docs/flex)
* [API keys and credentials](/docs/iam/api-keys)