---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/19003#article
headline: "19003: Contact with the unique_customer_provided_id provided already exists"
url: https://www.twilio.com/docs/api/errors/19003
inLanguage: en
dateModified: 2026-06-08T11:29:20.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 19003: Contact with the unique\_customer\_provided\_id provided already exists

Log Type: APPLICATION

Log Level: ERROR

## Description

This error occurs when you submit a contact with a `unique_customer_provided_id` that already belongs to an existing contact. Use `unique_customer_provided_id` as a unique identifier for one contact only. If you identify contacts from your own system with this field, keep that value mapped to a single contact record.

### Possible causes

* You created a contact with a `unique_customer_provided_id` that is already assigned to another contact.
* You updated a contact and changed `unique_customer_provided_id` to a value that already exists on a different contact.
* Your application sent more than one contact record for the same external customer identifier, so multiple contacts attempted to use the same `unique_customer_provided_id`.

### Possible solutions

* Find the existing contact that already uses the `unique_customer_provided_id`. If the request refers to the same person, update that contact instead of creating another one.
* If the request is for a different person, send a different `unique_customer_provided_id` that is unique in your source system.
* If the existing contact is no longer needed, remove or update that contact before you retry the request.
* Review your contact sync logic so each external customer record maps to only one `unique_customer_provided_id`.

#### Additional resources

* [Contact API](/docs/messaging/features/contact-api)
* [Compliance Toolkit for Programmable Messaging](/docs/messaging/features/compliance-toolkit)
* [Twilio Debugger](/docs/usage/troubleshooting/debugging-your-application)