---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/30516#article
headline: "30516: Toll Free verification rejection - Double opt-in required for this use case"
url: https://www.twilio.com/docs/api/errors/30516
inLanguage: en
dateModified: 2026-03-11T20:01:16.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 30516: Toll Free verification rejection - Double opt-in required for this use case

Log Type: APPLICATION

Log Level: ERROR

## Description

The Toll-Free phone number verification submission has been reviewed and it was rejected. Messaging traffic on this Toll-Free number is blocked until it's verified.

Verification is one component of ensuring A2P SMS is used by businesses in a legal and compliant manner. The review process looks at the business sending messaging (not the software powering it), the use case, sample content, the web presence, the opt-in/consent collected and associated website terms and privacy policies.

### Possible causes

Your messaging use case requires a double opt-in process, but:

* Only a single opt-in was provided
* The double opt-in process was not documented
* The confirmation step was missing or incomplete

Double opt-in is required for certain use cases including shopping cart reminders.

### Possible solutions

* Implement a double opt-in process for your specific use case
* Ensure the process includes:

  1. Initial opt-in (web form, keyword, etc.)
  2. Confirmation message asking user to confirm subscription
  3. User's affirmative response to complete enrollment
* Document the complete double opt-in flow in your submission
* Provide example messages for both steps of the double opt-in process

[Why was my Toll Free Verification Rejected?](https://support.twilio.com/hc/en-us/articles/9321443984155-Why-Was-My-Toll-Free-Verification-Rejected)

[Required information for Toll-free verification](https://support.twilio.com/hc/en-us/articles/13264118705051-Required-Information-for-Toll-Free-Verification)

[Toll-Free best practices](https://support.twilio.com/hc/en-us/articles/360038172934-Information-and-best-practices-for-using-Toll-Free-SMS-and-MMS-in-the-US-and-Canada)