---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/54051#article
headline: "54051: Invalid webhook URL"
url: https://www.twilio.com/docs/api/errors/54051
inLanguage: en
dateModified: 2026-06-08T11:29:20.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 54051: Invalid webhook URL

Log Type: TWILIO

Log Level: ERROR

## Description

Twilio returns this error when you set the `WebhookUrl` for a Sync Service to a value that is not a valid URI or is longer than 512 characters. Sync uses this URL when Sync objects are manipulated, and you can also enable webhook delivery for REST API-triggered events with `webhooks_from_rest_enabled`.

### Possible causes

* The `WebhookUrl` value is not a correctly formatted absolute URL. The Sync Service resource expects a `string<uri>` value for this parameter.
* You sent the request as `application/x-www-form-urlencoded` and did not percent-encode the `WebhookUrl` value correctly.
* The `WebhookUrl` value is longer than 512 characters.
* You supplied a relative or incomplete URL instead of a fully qualified webhook endpoint. Twilio examples use absolute webhook URLs such as `https://example.com/sync`.

### Possible solutions

* Set `WebhookUrl` to a fully qualified `http://` or `https://` URL that Twilio can call for Sync webhook events.
* If you build the HTTP request yourself, percent-encode the `WebhookUrl` value in the `application/x-www-form-urlencoded` request body before you send it.
* Keep the `WebhookUrl` value at 512 characters or fewer.
* Create or update the Sync Service with a valid `WebhookUrl` first, then enable `webhooks_from_rest_enabled` if you want Sync to send webhooks for REST API-initiated changes.

#### Additional resources

* [Service Resource](/docs/sync/api/service)
* [Sync Webhooks](/docs/sync/webhooks)
* [Getting Started with Twilio Webhooks](/docs/usage/webhooks/getting-started-twilio-webhooks)