Wireless providers, including Verizon, use systems similar to Voice Calling Spam Control powered by Nomorobo Voice to identify spam calls. These systems evaluate calls based on a scoring system. When calls exceed a certain threshold they are marked as SPAM, it is up to the Termination Provider receiving those scores to decide what scores should be marked as SPAM and what the tags state. It's important to note that these evaluations are largely based on the origin Caller ID (1NPANXXXXXXX) and are not directly related to STIR/SHAKEN protocols. This can be observed where some calls have the STIR/SHAKEN Checkmark on the cell phone but are still marked as SPAM. The STIR/SHAKEN signing token doesn’t always make it from the originator to the termination provider due to the complexities of the PSTN.
The most effective approach to combat this issue with AT&T, T-Mobile, and Verizon is to proactively register your Caller ID with freecallerregistry.com (for US numbers) or hiyahelp.zendesk.com (for Canadian numbers). Detailed instructions on how to register can be found at the end of this article. This service is provided by TNS and communicates with Hiya, First Orion, and TNS — providers that service AT&T, Verizon, and T-Mobile — ensuring your number is less likely to be tagged as SPAM. For the providers that allow it, we recommend submitting numbers in 11-digit format for best results. Typically, numbers are cleared of SPAM tags within 2-5 days; however, they may be re-flagged based on calling patterns or user reports.
It's advisable for legitimate businesses to register their numbers before they are tagged as SPAM. Certain businesses, like debt collectors or lead generators, may find it more challenging to avoid SPAM tags. Strategies such as acquiring new numbers, gradually increasing usage ("warming up"), and rotating numbers can help maintain a clean status.
Starting January 15th, 2024 we have seen an industry wide uptick in the number of calls being marked as SPAM on the Verizon Network or providers who use HIYA and First Orion. Numbers that are not registered in their databases may automatically be marked as SPAM. The process to remove numbers as SPAM takes 2-5 days. freecallerregistry.com submits to TNS/First Orion/HIYA all at once. You will receive email verification from each of them after submission.
On February 8th, TNS identified a bug that was introduced to their code that greatly increased the likelihood of calls being marked as SPAM industry-wide.