TransNexus charts three months of accelerating scam calls

TransNexus’s July robocall trends post says up front where its numbers come from: “The source data is from YouMail’s Robocall Index, a widely followed measure of robocall activity in the U.S.” This is a chart-and-commentary read of the same dataset, not a second measurement, and it is worth naming that before setting the two side by side.

What the trendlines show that a single month’s release does not: scam robocalls rose 14.2% from June to July, after rising 24.1% from May to June. That is three consecutive months of significant increases and the highest scam level in six months. Scam calls in July 2026 were up 8% against July 2025, while overall robocalls were down slightly year over year. The scam share went from 24% in June to 27% in July.

Overall July volume was up 1.5% on June, the highest in six months.

TransNexus does publish its own independent data, in a separate monthly series drawn from “hundreds of voice service providers using our STIR/SHAKEN and robocall prevention solutions” — terminating-side observed traffic rather than extrapolation from an app’s user base. Its July STIR/SHAKEN statistics report signed calls at termination reaching 54.3%, up 5.5% in the month: “This is the highest percentage of signed calls we’ve ever seen, and we’ve been tracking this for over five years. Great news, but still far from the level needed to deliver the full benefits of call authentication.” A-level attestation hit 33.7%, also an all-time high.

The same post carries the finding that pairs with the scam trend. Among the ten most prolific robocall signers, 98.6% of calls carried A-level attestation and none carried B-level.

Volume is falling year over year, signing is at a record, and the providers sending the most robocalls are the ones vouching hardest for them.