Three years into full STIR/SHAKEN enforcement, the caller authentication framework is working well at the top of the telecom ecosystem and poorly almost everywhere else, according to the Half Year 2026 Robocall Investigation Report from Transaction Network Services.
The nation’s seven largest carriers have stabilized at roughly 85% signed inter-carrier traffic, the vast majority carrying the top-level “A” attestation. But smaller communications service providers remain stuck at 19% to 20% signed traffic terminating to their networks, a figure TNS says has shown only single-digit improvement, and occasional backsliding, over several years. Legacy TDM/SS7 connections that strip call signatures are a primary culprit.
For an industry that lives and dies by answer rates, the more troubling finding may be what happens to calls that do carry proper credentials. TNS analytics tagged 10% to 12% of traffic that passed Verstat validation as unwanted, and 17% of confirmed spoofed calls arrived with “A” attestation. In other words, carrier analytics engines are not treating authentication as proof of legitimacy, and fraudsters are successfully obtaining top-tier credentials. TNS argues attestation alone “is not a silver bullet” and that layered analytics, reputation scoring, and branded calling are now table stakes.
That matters for collection operations because it confirms what many contact centers already suspect: even fully compliant, properly attested outbound campaigns are being scored by reputation algorithms that can flag or label calls regardless of their signing status. Rich Call Display claims fared no better, with as much as 27% of certain RCD-labeled traffic rated unwanted.
The fraud picture is intensifying the screening arms race. TNS documented AI voice cloning in high-risk incidents, multimodal voice-plus-text campaigns, and SIM box fraud that routes “A”-attested traffic through gateway farms. Scam scripts increasingly impersonate financial services, tax preparers, and government agencies, precisely the categories that make consumers warier of legitimate financial services calls.
On the regulatory front, the FCC continues advancing rulemakings focused on non-IP vulnerabilities, “Know-Your-Upstream-Provider” diligence, and stricter attestation accountability, while removals from the Robocall Mitigation Database are creating financial pressure on smaller providers.
Separate industry estimates cited in press coverage of the report put U.S. robocall volume at roughly 55 billion in 2025, with projections approaching 60 billion this year. For legitimate callers, every one of those calls makes the next consumer a little less likely to pick up.
