Insights

Elevate Your Voice and Messaging Security: Not All DNO Lists Are Created Equal

Aug 25, 2025

Protecting voice channels from spoofed and fraudulent calls is a shared priority across enterprises, especially in finance and telecom. But how you do it makes all the difference.

Many teams start with internal, manually built DNO (Do–Not–Originate) lists. But there’s a more powerful path forward — one that’s built for accuracy, scale and results.

From Manual to Managed: The DNO Shift That Changes Everything

Internal DNO lists often begin with the best of intentions. But over time, maintaining them becomes a drag on resources and a barrier to progress.

That’s where RealNumber® DNO comes in.

Developed and maintained by Somos, RealNumber® DNO offers registry-grade protection by tapping into authoritative numbering data across more than 6 billion phone numbers. It’s a fully managed solution that automates what internal lists can’t, so your teams stay focused on strategy, not spreadsheet upkeep.

What Makes RealNumber® DNO Different?

It’s comprehensive.
Sourced from the North American Numbering Plan and Toll-Free Number Registry, RealNumber® DNO covers unallocated, unassigned, invalid and subscriber set numbers commonly used in spoofing.

It’s always current.
Automatic updates ensure your protections stay aligned with real-time changes in the numbering ecosystem.

It’s easy to implement.
With simple API access and telecom-friendly integrations, it fits smoothly into your existing infrastructure.

When we stack up RealNumber® DNO against internal, manually built lists, the contrast is clear:

• Authoritative source vs. inconsistent data

• Real-time updates vs. manual refreshes

• Scalable and seamless vs. effort-intensive

And most importantly: better protection for your customers and your brand.

Fraud prevention doesn’t need to be a balancing act between effectiveness and effort. With RealNumber® DNO, organizations gain an edge that’s proactive, precise and built on trusted data.

Looking to evolve your DNO strategy?
This year, the FCC expanded its DNO order, requiring all carriers in the call path to block traffic from numbers that should never originate calls. Let Somos help ensure you stay compliant and make fraud prevention easier, smarter, and stronger. Contact us at connect@somos.com!