Voice Spam, Call Blocking & Whitelisting

Some of our customers who conduct legitimate voice business sometimes report that their outbound calls are getting marked with nuisance call labels, such as ‘Scam Likely’ or some variant based on an app, device or network. This can be frustrating and could result in your outbound calls going unanswered or even blocked.

Why my calls are being tagged as spam?

"Potential Spam", "Spam Likely", etc. are messages generated by cellular carriers, or applications downloaded by the end user, in order to warn their customers about a number that has had spam reports issued against it.

Since these caller IDs are added after the call is delivered to the cellular carrier, we, unfortunately, do not have any immediate control over how it's advertised.

What do I do if my calls are being tagged as spam now?

Register your numbers with each of the carriers or their call analytics providers. Registering your numbers will let them know who you are, that your use case is legitimate and your customers are expecting your calls. Registration as listed below is free.

However, while number registration often resolves mislabeling, it is not a whitelist or a guarantee of avoiding nuisance call labels in the future. Registered numbers can still be flagged again if certain call patterns are detected inconsistent with registered usage or if consumers file spam or fraud reports against them.

In summary, there are three key practices for removing and keeping your numbers free from mislabeling:

1. Register your numbers
2. Ensure you have complied with all relevant laws, regulations, and policies
3. Remain consistent in your calling behavior by phone number.

• Register your numbers for any case of mislabeling, or proactively for any new number you obtain. Registration to the three mobile providers or call analytics providers will cover the following carrier networks:

• Comply with TCPA requirements, FCC regulations, any other local requirements and Twilio’s Acceptable Use Policy.
• Avoid unusual spikes in traffic volumes, when possible. Analytics providers pay close attention to large swings in traffic which could indicate multiple use cases for a particular number, which is discouraged. However, some businesses are seasonal or provide emergency alerts, so traffic patterns are difficult to normalize. Always document your expected and normative call pattern description in detail - you may need to provide this information when attempting to overturn an erroneous tag.

• Other strategies to increase the likelihood of calls being picked up include:
• Multiple Caller IDs: Cycle through a set of valid caller IDs to reduce the total number of calls from a single number.
• Local presence: Obtain a number for every region, state, or area code you’re calling, and automatically change to that caller ID when calling that area.
• User Caller ID Name (CNAM): This displays the name of the calling party, minimizing the risk of someone tagging it as spam.
• Mix warm and cold prospects: Dial a mix of cold and warm prospects from the same line to help improve your overall rate of successful connections.
• Area mixing: Mix up the geographic area you are calling to spread calls over as many receiving carriers and call blocking systems as possible.
• Minimize abandonment rates: If you’re running a dialer, reducing your abandonment rate will reduce the likelihood you’ll be flagged as spam by a consumer.
• Register your number: Register your number with major caller ID reputation registries. Here is an example.
• Consistent phone number usage: Avoid using the same telephone number for multiple purposes.
• Comply with “Do Not Call” lists: Comply with the national registry of DNC lists and the DNC list for your own business.
• Keep your lists up to date: Remove phone numbers that don’t connect.