---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/81019#article
headline: "81019: Twilio phone number using deprecated API version"
url: https://www.twilio.com/docs/api/errors/81019
inLanguage: en
dateModified: 2026-03-11T22:03:37.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 81019: Twilio phone number using deprecated API version

Log Type: APPLICATION

Log Level: ERROR

## Description

The Twilio phone number connected to your Studio Flow is configured for the deprecated 2008-08-01 API, which is not compatible. Update the phone number API version to 2010-04-01.

### Possible causes

The Twilio phone number is configured for the 2008-08-01 API

### Possible solutions

Update the phone number API version to 2010-04-01