---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/51003#article
headline: "51003: Client Connection: identity too long"
url: https://www.twilio.com/docs/api/errors/51003
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 51003: Client Connection: identity too long

Log Level: ERROR

## Description

The `identity` value in your Access Token exceeds the maximum length allowed for a Twilio client connection. Twilio rejects the connection request when the token contains an `identity` that is too long.

### Possible causes

* Your application generates an Access Token with an `identity` string that exceeds the product limit.
* Your application passes unbounded user input, such as an email address, UUID collection, or concatenated account data, into the `identity` field.
* Your token generation logic appends environment, tenant, or session metadata to `identity`, causing it to exceed the allowed length.

### Possible solutions

* Shorten the `identity` value you include in the Access Token.
* Use a stable, compact identifier for each user instead of a long descriptive string.
* Update your token generation logic to validate the length of `identity` before creating the Access Token.
* If you need to associate additional user metadata with the client, store that data in your application instead of embedding it in `identity`.
* Review the Access Token documentation for your Twilio SDK product and confirm that your generated token matches the required client identity format.

#### Additional resources

* [Access Tokens](/docs/iam/access-tokens)
* [Conversations documentation](/docs/conversations)
* [Sync documentation](/docs/sync)