For stakeholders involved in the battle against robocalls, the September 2023 statistics related to STIR/SHAKEN and robocalls bring crucial insights. Compiled from data of numerous voice service providers using our robocall prevention and STIR/SHAKEN solutions, these stats highlight recent trends and the measures' effectiveness.

Robocalls Attestations: A Significant Rise in B & C Levels

In September, there's a notable increase in robocalls with B or C attestations.

Figure 1. Signed Robocalls by Attestation Last 6 Months

The graph reveals that robocalls with B-level attestation surged from 21.21% in August to 32.46% in September. Similarly, those with C-level attestation jumped from 16.18% in August to 26.78% in September. These are the peak numbers within the last half-year and throughout 2023. Furthermore, the overall percentage of robocalls increased from 6.45% in August to 8.02% in September.

STIR/SHAKEN Participation: Is Momentum Slowing Down?

The STIR/SHAKEN initiative has seen impressive growth, but recent numbers suggest a potential plateau.

Figure 2. Monthly Number of OSPs Sending Signed Calls

The figure shows the number of OSPs signing calls with just 8 new SHAKEN signers in September.

Figure 3. STIR/SHAKEN Authorized Providers by Month

As the graph displays, the number of SHAKEN authorized providers has been on the rise. Yet, with only 15 new providers in September, the growth rate might be stabilizing.

Coverage of STIR/SHAKEN: Some Setbacks and Slow Gains

Effective call authentication is vital for STIR/SHAKEN's success. The recent figures, however, present mixed results.

Figure 5. The Percentage of Signed Calls at Termination Last 6 Months

The chart indicates a downward trend. From 34% in July, the figure dropped nearly 3% in August, with only a 0.5% recovery in September.

Figure 6. Percentage of Calls with SHAKEN Attestation Levels Last 6 Months

This representation shows that calls with full attestation reached 24.5% in July but fell to 21.5% in August. September saw a slight increase to 22.5%.

Robocall Patterns Among Top Signers

The top SHAKEN-authorized providers, particularly prolific robocall signers, show distinctive patterns.

Figure 7. Robocall Percentage by Attestation—Prolific Robocall Signers by Robocall %

The figure indicates a steady growth in robocalls with A- and B-level attestations from these top signers. Astonishingly, 88.46% of their B-level attested calls and 79.4% of A-level attested ones were robocalls. However, the trend for C-level attested robocalls is declining.

For combatting robocalls effectively, considering the reputation of STIR/SHAKEN signers during call analysis is crucial.

In Conclusion:

• Robocalls with B- and C-level attestations have seen a sharp increase.
• The top robocall signers have higher percentages of A- and B-level attested calls.
• STIR/SHAKEN participation might be reaching a plateau.
• Coverage by STIR/SHAKEN dipped in August with only a minor recovery in September.

It's vital to monitor these numbers closely and adapt strategies to ensure that the fight against robocalls remains robust.