---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/51111#article
headline: "51111: Twilsock: Service instance limit reached"
url: https://www.twilio.com/docs/api/errors/51111
inLanguage: en
dateModified: 2026-07-14T12:30:02.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 51111: Twilsock: Service instance limit reached

Log Level: ERROR

## Description

Twilsock rejected the connection because your account reached the maximum number of allowed service instances. This usually means your application is creating more concurrent client connections or service instances than your current account limits allow.

### Possible causes

* Your application is opening too many concurrent Twilsock connections for the same account.
* Clients are reconnecting repeatedly because of a network issue, token refresh issue, or application logic that creates duplicate connections.
* Your application is creating new SDK client instances instead of reusing existing ones.
* Expected traffic increased beyond your current account limits.

### Possible solutions

* Review your application logic and make sure each client reuses an existing connection where possible instead of creating additional SDK client instances.
* Check for reconnect loops, duplicate initialization, or token handling issues that cause clients to open repeated Twilsock connections.
* Reduce unnecessary concurrent connections across your applications and environments.
* If the connection volume is expected and valid for your use case, contact Support to discuss increasing your account limits.

#### Additional resources

* [Programmable Chat documentation](/docs/chat)
* [Sync documentation](/docs/sync)
* [Help Center](https://help.twilio.com/hc/en-us)