Dear Valued Customer,

Hope you are all well and staying safe in this time of the pandemic. Recently, a few of you have raised the concern that your number is being displayed as SPAM CALLER or SCAM LIKELY to your candidates and/ or your customers. We want you to understand that we do not have any business relation with AT&T, T-Mobile, or Verizon, and we have no control over this issue. However, we are trying our best to understand this situation and find a solution for you. After talking to our vendors and doing our own investigation, this is what we found out.

To mitigate Anti-robocall and Caller ID Spoofing on January 7th, 2021 the President signed into law the TRACED Act, which is aimed at curbing unwanted robocalls. 

The TRACED Act is expected to primarily affect the practices of telephone carriers and entities that transmit high volumes of robocalls. It could, however, have a broader effect on entities that transmit large volumes of calls, including live-voice calls. This is because the new law requires the adoption of the SHAKEN/STIR call authentication framework that, depending on its implementation, can end up blocking calls from numbers that transmit high volumes of calls.

This is being tested by our vendors at present.

How Do Numbers Get Flagged?
 Your outbound phone number can receive flags in one of two ways. Either by the consumer manually blocking your number through a call blocking app or by the carriers if you are making too many outbound calls.

Carriers flagging numbers
Most carriers have built-in thresholds that monitor call activity. If a single number is making, for example, more than 10 calls a minute, more than 100 calls a day, or over a certain amount for a week, it can be determined that this activity is not originating from human dialing. In these instances, the carrier can assign a flag score to your number indicating that it is likely robocalling.

This type of flag can be avoided by ensuring the dialer you are using is configured correctly. Using the wrong dialer type, like a power dialer, can cause your number to make more outbound calls to connect. While an agent may only speak with a few leads per hour, their phone may be dialing dozens of times.

Swapping out your DID numbers throughout the day is also a safe strategy to use if you are managing a high-volume call center. Once a number reaches its calling threshold for the day it should be swapped out for a different number. This can help to ensure your number does not receive a flag for suspicious calling behavior.

Each carrier monitors behavior in its own way, and the overall process is not publicly available. Ultimately, letting your number cool off by having several numbers you can swap out can help reduce the carrier flag over time. 

Consumers flagging numbers
While your dialing practices can reduce the risk carrier flag, your business is still used by your customer. With an abundance of call blocking apps, if a person is having a bad day, or your agent has a bad interaction with a prospect, your number can get flagged.

With scam likely caller ID tools, one block will likely not lead to a flag on your number. However, if the app. sees that your DID is receiving multiple blocks, they will label your number as either a “SPAM CALL” or “SCAM LIKELY”.Typically, call blocking apps only work with particular carriers. If your number gets flagged on a particular app., your caller ID may only show SPAM CALLER or SCAM LIKELY on some carriers. Due to the fragmentation of the data, this means that some people will see SPAM or SCAM while others will not.

Erroneous number flagging
In addition to the above, it is possible that your numbers might get “spoofed” by scammers causing the number to get flagged. Or in some instances, consumers who simply do not like your brand might flag your number causing it to get blocked.

How to Deal with Flagged Numbers
While having a way to dispute a flag would be ideal, there is no clear system in place for this. The carriers and other third parties creating these scam likely caller ID tools are doing so in an effort to protect consumers, not businesses. A business can attempt to contact the carrier or call the blocking app to dispute a flag, but communication is often difficult and may not yield any results.

Let your numbers cool off
Pull your flagged numbers from your dialer to avoid them affecting your business and obtaining more flags. Keeping your numbers off the dialer for a while might allow your flags to fall off over time. Keeping additional DIDs available to swap out is a good idea.

Frequently monitor your numbers for flags
Scanning your DIDs often helps ensure you aren’t dialing from flagged numbers. While you may not be able to avoid getting a flagged number, you can swap out your numbers once they’ve received flags. Getting a few flags won’t automatically yield a “scam likely” caller ID, however the more flags your number receives increases the likelihood of this.

To avoid interruptions caused by numbers getting flagged as Spam Caller or Scam Likely we would recommend:

Place test calls to numbers on various carriers to see which carriers mark you as Spam Caller or Scam Likely.
Use virtual numbers or 800 numbers as the number that shows on the caller ID
Purchase new numbers for your outbound dialing

Below is what our Vendor commented on this matter:
When "Spam" or "Scam Likely" shows on a destination's handset, this is oftentimes due to (mostly cell carriers) term carriers implementing their own CNAM value per the internal database they manage. We do know that AT&T and T-Mobile for example have their own database that can overwrite any data that is projected. These term-side customers/destinations will need to request this source number be whitelisted, as we do not have a business relationship with them to request, to remove this value. I have provided links below so you can ask your customers to reach out to these carriers (as they are in business with them) to request they remove the label regarding the required DID.





US Carrier Call Blocking

VoIP Office has become aware that major carriers in the US industry are actively blocking calls to their subscriber's devices due to them deeming the calls as potentially fraudulent, where end users may see "Fraud Risk", "Spam Risk", "Potential Spam", "Robocaller", "Scam Likely" and other names which their carriers are prepending onto your caller IDs. 

We are seeing, that high volume calls from non-rotated caller IDs are experiencing a higher amount of user busy responses in the form of a SIP 480/486 Busy Here.

In some cases, it's also being reported that the carriers of the destinations are using services that are categorizing calls as "Potential Spam" on the user's devices. 

How to use Whitelisting

We also understand that there are many valid & legitimate use cases, where there is a necessity for high volume calls (e.g. alerts, appointment reminders, etc.) Providers and their analytics partners have established mechanisms for callers to seek redress to fix any inadvertent call labeling or blocking concerns, as well as to register their numbers in the first instance.

VoIP Office recommends that our customers actively submit a whitelisting request to the major carriers, in order to disclose your use case and in turn prevent your outbound calls from being blocked and/or showing unwanted classified names on your caller ids. 

Please see the below websites where you can submit these requests. 

As well as a broader list of other carriers here.


We are committed to combating spoofing and illegal robocalling by implementing the industry-wide STIR/SHAKEN solution, in an effort to play our part in reducing these illegal occurrences.