As robocalling and spam calls become increasingly widespread, legitimate businesses often struggle with their outbound calls being labeled as "Likely Sales", "Spam Likely", or "Scam Likely". This can lead to lower answer rates and reputational harm.
There are many factors within the spam ecosystem that contribute to this, but CloudTalk's experts are here to help your business navigate these challenges and ensure your calls reach the right audience.
How Do Calls Get Labeled as Spam?
Telecom operators use analytics engines to monitor call traffic patterns and flag suspicious activity. These engines label calls as likely sales, spam, or scam to protect consumers from potentially harmful calls.
Unfortunately, these systems can sometimes mistakenly flag legitimate business calls. The specific algorithms used are not publicly disclosed and are regularly updated to prevent abuse by spammers.
In the U.S., the three major carriers each rely on their own analytics partners:
Verizon – TNS (Transaction Network Services)
T-Mobile – First Orion
AT&T – Hiya
The good news is that there are both common sense best calling practices and carrier registrations and anti-spam tools at businesses' fingertips to avoid mislabelling and flagging.
1. Traffic patterns - the way you're calling
2. Number inventory - the numbers you use to call
3. Number registrations - how you protect your numbers with operators
1. Call Traffic: Best Calling Practices
If you're planning large-scale campaigns or using CloudTalk Dialers, following these best practices will help maintain a positive caller reputation, avoid spam flags, and improve answer rates.
Traffic Patterns That May Trigger Spam Labels
Spam Trigger | What You Can Do |
Sudden spikes in call volume (e.g. new number suddenly making hundreds of calls) | Maintain a consistent outbound call volume and avoid sudden spikes in traffic that deviate from regular patterns. |
Excessive calls from a single number | Spread calls across multiple numbers. Give each agent their own number. |
Low Answer Rates: | Use numbers with local proximity - in the U.S. we can get numbers from all major cities and towns. Call during optimal business hours. If unanswered, use voicemail drop. |
Short-Duration Calls or High Abandon Rates | Target verified leads. Ensure calls last at least 15–30 seconds. |
Repeated unanswered calls to same numbers | Keep contact lists clean. Remove unresponsive numbers. |
Frequent blocking or spam reports: If many recipients block your number or report your calls as spam, your number may be permanently flagged. | Abide by local telco regulations (both in your country and the recipient country). Only call opted-in contacts. Honor opt-out requests: If a callee asks you not to contact them anymore, remove their number from any further contact. |
Calling numbers on Do Not Call (DNC) lists | Ensure compliance with local DNC registries (e.g. https://www.donotcall.gov for the U.S.). |
2. Number Inventory: Best Practices
Segment your number inventory
To minimize the risk of your calls being flagged as spam, it’s essential to segment your number inventory. Separate numbers based on use cases and avoid reusing the same number for multiple purposes.
Inbound “Clean” Numbers
Use these for public-facing purposes only:
Official website, advertising materials, or online campaigns.
These numbers should only receive inbound calls or be used for outbound communication with established contacts.
If they aren’t used in outbound campaigns, they’re much less likely to be flagged — meaning no need to replace them later and no risk of losing numbers printed on marketing materials or customer touchpoints.
Outbound Sales or Campaign Numbers
Use different numbers specifically for outbound campaigns or sales activities.
These numbers are more likely to be affected by your call volume and patterns.
Having a separate pool makes it easier to cycle out flagged numbers and protects your permanent inbound numbers from reputational damage.
3. Number Registrations
Even with the best practices in place, high call volumes can still cause numbers to be flagged. To improve outbound reachability and avoid unnecessary call blocking, follow these steps:
A. Register Numbers in Hiya Connect
Hiya Connect registers your numbers in carrier-level spam detection systems. This is one of the most effective ways to protect your outbound numbers and improve contact rates.
Why Hiya Connect?
Each U.S. carrier uses its own analytics engine:
T-Mobile → First Orion
Verizon → TNS (Transaction Network Services)
AT&T → Hiya
Hiya Connect not only covers these major analytics engines but also:
Works with Samsung devices globally
Syncs with all Hiya-partnered carriers worldwide
Alternatively, you can register your numbers individually with each U.S. carrier or use the Free Caller Registry, a unified portal supporting all three engines. But Hiya remains the strongest and most comprehensive option.
B. Enroll in STIR/SHAKEN Verified Calling (USA only)
STIR/SHAKEN is a set of call authentication protocols designed to block fraudulent and illegal robocalls. U.S. telecom carriers use this framework to verify the legitimacy of calls by checking their origin through authentication tokens.
At CloudTalk:
All U.S. outbound calls are sent with STIR/SHAKEN verification.
For stronger protection, we can register your business and numbers with carriers to ensure your calls receive an A-level Attestation, the highest trust rating.
This significantly boosts your caller legitimacy and helps avoid unnecessary blocks.
You can read more about Attestation-levels and follow our registration guides here.
4. Call Branding
Making your calls recognizable at first glance builds trust and increases answer rates. There are two ways to brand your outbound calls:
CNAM (Caller ID Name)
CNAM displays a business name (up to 15 characters) on the recipient’s Caller ID.
See our guide to CNAM enrolment
Key Details:
CNAM uploads your business name to a centralized database used by telecom carriers.
Currently supported only in the United States.
It relies on decentralized databases originally built for landline networks, which can lead to inconsistencies or outdated caller info.
Offers limited control over how your business appears to the recipient.
Branded Calling (coming soon)
Branded Calling is a more modernized solution than CNAM.
Unlike basic CNAM, Branded Calling gives your business the ability to:
Display a custom name (up to 32 characters),
Add your brand logo,
Include a call reason (e.g. “Delivery Update” or “Appointment Reminder”).
These details appear on supported devices and carriers — significantly improving brand recognition, trust, and answer rates.
Have more questions? We have answers. Reach out to our Support team. We're always happy to help!