Signed-call coverage reaches 48.8% in TransNexus's June STIR/SHAKEN data

TransNexus’s June STIR/SHAKEN numbers put signed calls at termination at 48.8% — up 3.3 points on the month and, by their measure, the highest in 20 months. Full A-level attestation reached 30.8% of calls (up 1.1), and the count of originating providers observed signing calls rose 2.2%.

The figures are drawn from traffic reaching TransNexus’s own customers, so the absolute level reflects that footprint rather than the whole US network — but as a consistent monthly series it remains one of the better public reads on whether coverage is actually moving. Nearly half of terminating calls signed is a real improvement; it is also, as TransNexus notes, still well short of the level where authentication delivers its full benefit. Robocalls held around 3.5% of all observed calls, roughly flat on May.

A data point to keep for cross-referencing against the TNS and Hiya annual reads — the signed-coverage line is the one worth watching climb quarter over quarter. It feeds the running series on our data dashboard, where June’s 48.8% is the latest point against YouMail’s volume line.