FCC DNO Mandate Explained: How TNS Helps Providers Stop Spoofed Calls, Podcast

Sarah Halko, Head of Regulatory and Industry Relations at TNS, joined Doug Green, Publisher of Technology Reseller News, for a Cloud Communications Alliance (CCA) podcast focused on the FCC’s Do Not Originate (DNO) mandate and its role in combating robocalls and caller ID spoofing.

Halko explained that DNO (Do Not Originate) identifies phone numbers that should never be used for outbound calling—such as invalid, unallocated, or inbound-only numbers like government agencies. Blocking calls that spoof these numbers allows service providers to stop obvious fraud earlier in the call path, before it reaches consumers.

While DNO began as an optional tool in 2017, regulatory expectations have steadily increased. As of December 15, 2025, every service provider in the call flow must maintain a “reasonable DNO list,” making accurate, up-to-date data essential for compliance.

“Without reliable, authoritative numbering data, service providers can’t confidently determine which calls should be blocked,” Halko said. “DNO compliance ultimately depends on knowing how numbers are assigned, used, and routed in real time.”

TNS supports providers by delivering trusted, continuously updated numbering and routing intelligence across the U.S., Canada, and the Caribbean. This enables earlier, more accurate call blocking and reduces the risk of false positives or missed fraudulent traffic.

Looking ahead, Halko emphasized that DNO is only one part of a broader trust framework that also includes analytics, traceback, authentication (STIR/SHAKEN), and Know Your Customer practices—all working together to protect network integrity.

Learn more: https://tnsi.com/