---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/17516#article
headline: "17516: Participants must include at least one CUSTOMER"
url: https://www.twilio.com/docs/api/errors/17516
inLanguage: en
dateModified: 2026-07-31T15:59:35.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 17516: Participants must include at least one CUSTOMER

Log Type: APPLICATION

Log Level: WARNING

## Description

Twilio cannot create a new transcription because no participant is assigned the type `CUSTOMER`. Conversation processing requires at least one `CUSTOMER` participant.

### Possible causes

* No participant is designated as `CUSTOMER`.
* All participants are designated as `HUMAN_AGENT` or `AI_AGENT`.

### Possible solutions

Designate at least one participant as `CUSTOMER`.

#### Additional resources

* [Specify participant information](https://www.twilio.com/docs/voice/api/batch-transcription-resource#specify-participant-information)