---
page_type: error
code: 31503
message: "31503: Service Unavailable"
level: ERROR
product: Programmable Voice
---

## Description

## Error - 31503

### Service Unavailable

The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. This error can also be caused by the Application SID provided in the access token pointing to an inaccessible URL.

### Possible Causes

- The server is under maintenance.
- The Application SID provided in the access token points to an inaccessible URL.

### Possible Solutions

Please check the Application SID URL. For further assistance, please reach out to Twilio Support through the [Console](https://console.twilio.com) or [Help Center](https://support.twilio.com).