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Outbound Calls Blocked or Labeled as Spam or Scam Likely

Table of Contents

What is a nuisance call label?

Customers who conduct legitimate voice business may notice that their outbound calls are getting marked with nuisance call labels, such as ‘Scam Likely’, 'Spam', ‘Fraud Risk’, 'Robo Call' or some variant based on an app, device or network. This can be frustrating, and could result in outbound calls going unanswered or even getting blocked. 

These labels and any other resulting call blocks / filtering is done by the called party, their carrier, or their analytics partners, not Twilio. Because Twilio is not the party filtering these calls or adding the labels, we have limited ability to remedy the issue. There are some actions you can perform to potentially eliminate the labels and/or call blocking, but this is not guaranteed. 

This article outlines all the steps you can perform to put your business in the best position to avoid blocked / filtered calls and nuisance labels. 

How do I remove a nuisance label or call filtering from my Twilio phone number?

Here are a few steps you can take to address nuisance labels and blocked calls / call filtering on your Twilio phone number.

  • US Numbers: Register your US numbers with the FCC. The FCC established this free registry site,, which covers the main analytic companies that support major US wireless carriers that can remove a negative label on a call.
  • International Numbers: At this time Twilio is not able to assist with removing nuisance  labels from international numbers. Please reach out to the terminating carrier that is marking your calls as spam and work with them to register your number or correct the nuisance label.
  • Signing up for SHAKEN/STIR may increase the likelihood of answered calls by increasing consumer trust of the caller.
  • Signing up for Voice Integrity can prevent/end call filtering and nuisance labels by registering your Twilio numbers with the analytic engines for Tmobile, Sprint, and AT&T (Verizon coming soon). This eliminates the need to register your numbers with the FCC (mentioned above) and creates a higher level of trust for these analytic companies to avoid call nuisance labels and filtering.  
  • Updating or Adding CNAM on your phone numbers may increase the likelihood of answered calls by providing accurate caller information to your customers, but please note that this will not affect nuisance labels or blocked calls.
    • See the full guide here on Getting Started with CNAM Caller ID
    • CNAM stands for Caller ID Name. CNAM is a feature in the United States public telephone network that identifies an incoming caller by a personal or business name associated with the originating phone number. You can also choose to remove any CNAM currently assigned to a number. This is helpful when you purchase a new number as CNAMs are not automatically removed when users release ownership of a number.
    • Here are a few ways you can submit CNAM change requests:
    • CNAM will not remove a Nuisance label, but may increase answer rates due to the proper display of caller information applied to the call.

Will registering my number resolve mislabeled calls?

While number registration often resolves mislabeling or blocking, it is not an allowlist or a guarantee of avoiding mislabeled calls in the future. Registered numbers can still be flagged again if certain call patterns are detected, inconsistent with registered usage or if consumers submit spam or fraud reports against the number. 

Therefore, we recommend the following key practices:

Should I register numbers I just purchased?

Yes, nuisance labels are not automatically removed from a number when the previous owner releases them. It is a best practice to register any newly purchased numbers.

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