---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21240#article
headline: "21240: Credential List Validation Error"
url: https://www.twilio.com/docs/api/errors/21240
inLanguage: en
dateModified: 2026-03-11T18:38:39.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21240: Credential List Validation Error

Log Type: APPLICATION

Log Level: ERROR

## Description

One of the parameters passed when creating or updating a Credential List was incorrect.

### Possible causes

* A Credential List with the same FriendlyName may already exist
* A Username was not provided. A Username must be provided and it must have 32 characters or less
* The password was not provided. A password is required that meets the following criteria:

  * Minimum 12 characters
  * At least one mixed case
  * At least one digit

### Possible solutions

* Ensure that your Credential List meets the validation requirements.