With spam calling on the rise, telephone companies have implemented call screening on behalf of subscribers. Although this has blocked a large portion of ingress spam on the telecom networks, these systems can have a negative impact on businesses reaching consumers over the voice channel. To prepare for and/or resolve "scam/spam likely" we recommend following this best practices guide in this order:







Mobile Carrier Operators

The top 3 Operators make up approximately 323 million subscribers and represents about 80% of the mobile market. Each of these providers have implemented both internal systems to identify and block spam calling patterns, and utilize partners (below in chart) to identify spam callers based on user feedback and crowd-source data. For the purposes of this article, we will mainly focus on these top 3 providers.


STIR/SHAKEN is implemented at the voice provider network level to attest to the veracity of the calling party's number. The purpose of STIR/SHAKEN is to combat the use of caller IDs owned by others - this practice is commonly referred to as "spoofing". As a customer of Ytel, this process is handled for you automatically and there is nothing you need to do. You can read here how Ytel was one of the first companies to implement STIR/SHAKEN on behalf its customers.

A few notes on STIR/SHAKEN;

  • STIR/SHAKEN is required by the FCC

  • Ytel signs your calls with A-Level attestation, the highest level possible

  • STIR/SHAKEN is only supported on local phone numbers

  • STIR/SHAKEN is not supported on Toll Free Numbers

  • STIR/SHAKEN does not apply to the SMS ecosystem (text messaging)

  • Read more about STIR/SHAKEN here


Caller ID Naming (CNAM) is a service that associates an Individual's Name or Company Name with a phone number. CNAM increase the reputation of calling number and can decrease the possibility of being identified as "scam/spam likely". It may also increase consumer answer rate, because the calling party is identified.

How Does Caller ID Work- Your Quick Guide Before Calls

To set CNAM in the Ytel user portal:

Login to app.ytel.com and Navigate to Settings -> CNAM Management

Next, click...

A CNAM can use both letter and number characters, but must start with a letter. Maximum length is 15 characters including spaces, however we recommend not using spaces when possible. We also recommend using different names for different departments such as "Ytel", "Ytel Sales", "Ytel Support".

It takes up to 3 business days for Ytel to approve CNAM. Ytel is only able to approve CNAM requests that are your registered DBAs or legal entity names. After approval, the Ytel User will need to apply CNAM to a specific number set. You can do this by clicking Number Sets in the the left hand navigation pane.

Then click one of your number sets. If you don't have one, click create number set.

Click CNAM Settings

Select the CNAM you wish to use for that number set

Ytel sends regular updates to the central CNAM database used by major carriers every 30 minutes.

*Please note the following in regards to the success of CNAM

  • Your caller ID may appear one way on one network, completely different on another, and/or not at all. While consumers notice little difference, businesses can experience a wide range of results while testing due to this fragmentation. CNAM supports showcasing your brand, but is not guaranteed to show on all available devices and/or carriers.

  • It can take 30 days (or longer) for the major carriers to update internal systems to look for new CNAM data submitted by Ytel.

  • When/if the carriers display CNAM, it may overwrite previous words such as SPAM-Likely or Telemarketing if accompanied with a STIR/SHAKEN validated phone call + registration with TNS, Call Transparency, and HIYA.

  • When CNAM was first introduced, Mobile Network Operators would charge consumers for the service. Be aware some of your customers may be on old cell phone plans that need this feature turned on to see Caller Names.

  • It is common for older phones, including phones with older operating systems, not to support CNAM.

  • Most pre-paid phones/plans services do not support CNAM.


  • Comply with all "Do Not Call" lists, and other Telephone Consumer Protection Act (TCPA) requirements; as well as State and local laws.

  • Don’t contact people that don’t want to be contacted. Receiving a single complaint will flag a number for further review by the carriers.

  • We recommend a range of calling a customer between 1 - 3 times per day, maximum. Calling the same number multiple times in a day or multiple days in a row will likely result in the calling number (your number) becoming flagged.

  • Numbers being called should not be grouped or sorted in a way that generates a pattern.

  • Avoid mirroring the first few digits of the destination phone number in the from number. This is commonly known as "neighborhood spoofing". Network operator call screening algorithms are aggressively monitoring for this behavior. Calling numbers should be from office area codes or from an area code where your employee is located.

  • Mobile carriers will mark a number as spam if they are hanging up on voicemails on a regular basis. Avoid this practice by leaving a human answering machine message.

  • Avoid short duration calls by making sure your average call lengths are greater than 60 seconds. This indicates consumers are willing to talk to your employees past a "hello" and establishes a pattern of trust with the carriers.

  • Keep your calling list(s) manicured. Low call completion rates are often associated with unwanted calling behavior.

    • Remove contact numbers from your systems that don’t connect.

    • Do not call unassigned or disconnected numbers.

    • Do not engage in the practice known as “war dialing”.

  • Provide consumers with a clear identification of who is calling, along with easy to understand directions for opting-out of future calls.

  • Provide a telephone number and/or other contact information - answered by a human - that consumers can use to report alleged violations.

Be consistent in your phone number usage

  • Use one telephone number for a single purpose (i.e. one each for marketing, surveys, or customer service callbacks). To help reduce the likelihood of your calls being flagged, we recommend aligning the context and content of your calls over a specific phone number throughout the life of your campaign. We also recommend using different CNAM names for different departments such as "Ytel", "Ytel Sales", "Ytel Support". See the CNAM section for more information.

  • Phone numbers that have been reassigned for other purposes should go through a 45-60 day waiting period before being reintroduced for use in a new campaign. Review the CNAM being used and ensure it is consistent with the call purpose.

Be consistent in your outbound call volume

  • We recommend users attempt to maintain a regular traffic volume, without unusual spiking.

  • When starting a new campaign, it’s best to gradually ramp-up your volume incrementally, instead of going full speed on day 1.

The R.M.R. Formula: Register Monitor Remediate

Start by reviewing this article on Spam Likely It contains all the steps and instructions necessary to implement R.M.R. into your daily activities.


You can register phone numbers by visiting FreeCallerRegistry.com - After you submit information to this website, each carrier will e-mail you independently with their individual process.

T-Mobile Call Reporting - Is T-Mobile improperly blocking your calls to their subscribers? You can take steps to inform T-Mobile directly by clicking here.

3rd Party Apps - Many 3rd party apps exist and Ytel is looking into solutions to register phone numbers with these apps (not yet available). Here is a list of popular apps if you choose to contact them yourself.





Call Control


Mr Number

Should I Answer?

Avast Mobile

Norton Mobile Security

Call Blocker



Call Bliss






With our Number Reputation monitoring service (available independently or as part of Trust Center), Ytel provides you with the ability to monitor your numbers for FTC complaints. In addition, the services provides our spam/scam monitoring service.

  • Learn more here.

Is your number being labeled "Telemarketer" "SCAM" or "SPAM-Likely"? Mitigation may be possible. You can contact carrier 3rd party systems directly by following the links below:

AT&T/HIYA Contact
T-Mobile/Call Transparency


If you are working with Ytel on REGISTERING, MONITORING, and REMEDIATING phone numbers it is very important you send all communication through Ytel and work with us closely to avoid wrong or duplicate information being received by the Carriers. The process to mitigate a phone number can be time-consuming and expensive and should be done with extreme care. Also note that third-party spam-likely monitoring systems exist to monitor phone numbers but their testing will not reflect an actual call being sent from the Ytel network to a consumer handset as they will not be able to pass STIR/SHAKEN A-Level attestation. We recommend practicing extreme care to avoid your numbers being accidentally flagged as spam-likely.

As the telecommunication and carrier ecosystems continues to change and evolve, so will this article - check back for regular updates.

The information contained in this article is not legal advice and should not be interpreted as such. It is intended for informational purposes only.

We're here to help - if you need assistance, please contact the Ytel support team via email at support@ytel.com or you can click the live chat button at the bottom right of your screen.

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