---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/19042#article
headline: "19042: Custom Field validation error"
url: https://www.twilio.com/docs/api/errors/19042
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 19042: Custom Field validation error

Log Type: APPLICATION

Log Level: ERROR

## Description

The request contains one or more invalid values for a Flex custom field. This error occurs when the custom field payload does not meet the expected validation rules for type, format, or allowed length.

### Possible causes

* A custom field value exceeds the maximum allowed length.
* A custom field value uses the wrong data type, such as sending text where a number, boolean, or date is expected.
* A date value is not in the expected format.
* A required custom field value is missing from the request.
* The request includes a value that does not match the validation rules configured for that custom field.

### Possible solutions

* Review the request body and confirm that every custom field uses a valid value for its configured type.
* Verify that string values do not exceed the allowed length for the field.
* Check that date values use the format your Flex configuration expects.
* Remove unsupported or malformed values from the request before sending it to Twilio.
* Compare your request with the Flex API resource you are updating or creating and correct any field-level validation issues.

#### Additional resources

* [Flex documentation](/docs/flex)