The communications industry has made significant progress in restoring trust in the telephone network. STIR/SHAKEN has given us a way to identify who signed a call and the level of attestation they are making. But there is still a fundamental question we cannot reliably answer:

Was the provider that originated the call actually chosen by the business whose number is being presented?

Today, the answer is often no more than an assumption.

Enterprises may work with multiple originating service providers (OSPs), CPaaS platforms, contact centres or other communications providers. Those relationships are legitimate and knowable to the enterprise—but they are largely invisible to the wider communications ecosystem.

This creates an important gap. A provider can sign a call with Attestation “A”, yet there is currently no shared mechanism for the rest of the ecosystem to verify that the enterprise actually authorized that provider to use its numbers.

Extending DNO

DNO+ (Do Not Originate Plus) builds on the familiar and proven DNO concept.

Rather than simply identifying numbers that should never originate calls, DNO+ (Do Not Originate Plus) allows an enterprise to declare which providers are authorized to originate calls on its behalf.

The principle is straightforward:

A legitimate enterprise call should originate only through a provider the enterprise has explicitly authorized.

DNO+ (Do Not Originate Plus) uses the existing relationship between the enterprise and its provider, including Know Your Customer (KYC) processes and verified Right-to-Use (RTU) information for the telephone number. The authorized provider is then recorded in a DNO+ (Do Not Originate Plus) declaration.

When a call is received, the signing provider can be compared against that declaration.

If the provider is authorized, the Attestation “A” claim has objective, enterprise-backed support.

If the provider is not authorized, the call can be identified as unauthorized—regardless of the attestation level it claims.

Why this matters

This is not about replacing STIR/SHAKEN, branded calling, analytics or existing fraud controls. It is about giving those mechanisms a stronger foundation.

For enterprises, DNO+ (Do Not Originate Plus) provides a clear way to say: these are the providers we have chosen to use our numbers.

For originating providers, it provides a way to demonstrate that their attestation is backed by the enterprise itself.

For terminating providers and analytics platforms, it provides an additional, objective signal that can help distinguish legitimate enterprise traffic from spoofed traffic.

Most importantly, it changes the conversation from “Who signed this call?” to “Was that provider authorized to sign it?”

Simple by design

DNO+ (Do Not Originate Plus) is deliberately designed to be operationally straightforward. Providers already perform DNO checks. DNO+ (Do Not Originate Plus) adds one additional comparison: does the signing provider’s identifier appear in the enterprise’s authorized provider declaration?

It does not require a new numbering authority or a completely new technical infrastructure. It builds on existing numbering, KYC, RTU and STIR/SHAKEN mechanisms.

That simplicity is important.

The communications ecosystem does not need another complex system. It needs a clearer way of establishing trust.

Building trust across the ecosystem

DNO+ (Do Not Originate Plus) becomes more valuable as adoption grows.

Every enterprise that publishes its authorized providers creates a known-good reference for its telephone numbers. Calls that do not match that reference become identifiable exceptions rather than unexplained anomalies.

This also creates an incentive for providers to follow good attestation practices. Providers authorized by enterprises can demonstrate that their “A” attestations are genuinely backed by the number holder. Providers repeatedly signing calls they were never authorized to originate become much easier to identify.

The objective is simple:

Make legitimate enterprise calls easier to trust—and unauthorized calls harder to hide.

DNO+ (Do Not Originate Plus) is a relatively small extension to an established industry practice, but it has the potential to make a significant difference to trust in enterprise communications.

If we can establish trust before traffic is originated, rather than trying to determine legitimacy after a suspicious call has already reached the consumer, we can create a healthier communications ecosystem—one where legitimate business calls get through and impersonators do not.

That is the purpose of DNO+ (Do Not Originate Plus). Read the full Framework document HERE

Author

CFCA Trust & Transparency Working Group