19020: Contact with the provided channel value already exists

You tried to create or update a contact with a channel value that is already assigned to another contact. A channel value must be unique for each contact, so Twilio rejects the request when the same identifier is already in use.

• The request includes a phone number, email address, or other channel value that already belongs to an existing contact.
• Your application is retrying a create request and is sending the same channel value again.
• Your contact matching or deduplication logic did not check whether the channel value already exists before creating a new contact.
• You are trying to add a channel value to a new contact when that value should be updated on the existing contact instead.

• Search for an existing contact that already uses the channel value before you create a new contact.
• If the channel value belongs to the same person, update the existing contact instead of creating another one.
• If your application retries failed requests, make sure your retry logic does not create duplicate contacts with the same channel value.
• Validate incoming channel values in your application and enforce uniqueness before you send the request.
• If the channel value is incorrect, correct it and submit the request again.

• Twilio Segment