STIR/SHAKEN statistics from March 2024

The March 2024 STIR/SHAKEN and robocall statistics are now available. The data show the latest trends in robocalls, STIR/SHAKEN participation and attestation level usage.

We’ve been publishing monthly STIR/SHAKEN statistics since April 2021. These numbers are gathered from well over a hundred voice service providers using our STIR/SHAKEN and robocall prevention solutions. The data describe calls they received from 962 other voice service providers that originated calls, including some robocalls, signed with STIR/SHAKEN.

Many robocalls are signed with B or C attestation

Robocalls unchanged across all attestation levels

Line chart comparing robocall attestations over 6 months

Figure 1. Signed Robocalls by Attestation Last 6 Months

Figure 1 shows robocalls by attestation level over the past six months. Robocalls were unchanged across all attestation levels.

STIR/SHAKEN participation and coverage

We measure STIR/SHAKEN participation changes in two ways:

  1. The number of Originating Service Providers (OSPs) signing calls received by our customers,
  2. Service providers authorized to do SHAKEN by the STI Policy Administrator (STI-PA),

SHAKEN signing up slightly

line chart showing the number of originating providers sending signed calls

Figure 2. Monthly Number of OSPs Sending Signed Calls

Figure 2 shows the number of Originating Service Providers (OSPs) signing calls. We saw 26 new SHAKEN signers in March, a 2.8% increase.

The number of SHAKEN-authorized providers up slightly

line chart showing an increase in SHAKEN participation

Figure 3. STIR/SHAKEN Authorized Providers by Month

Figure 3 shows the number of SHAKEN authorized providers. There were 33 additional SHAKEN-authorized providers in March, a 2.6% increase.

These two measures show that the STIR/SHAKEN participation increased slightly.

STIR/SHAKEN coverage

Signed calls at termination level

line chart showing the percentage of signed calls received at termination

Figure 4. The Percentage of Signed Calls at Termination Last 6 Months

Figure 4 shows the percentage of signed calls at termination for the past six months. This statistic was 37.0% in March, down slightly from 34.7% in February.

This level of coverage is still too low for effective use of call attestation information by terminating providers. The primary reason for low STIR/SHAKEN coverage is widespread non-IP interconnections across the telephone network.

Calls with full attestation level

line chart showing the percentage of calls received at termination by attestation level

Figure 5. Percentage of Calls with SHAKEN Attestation Levels Last 6 Months

Figure 5 shows the percentage of calls signed by attestation level. Calls signed with full A-level attestation were 26.51% in March, down slightly from 26.86% in February. The change is so small, we’ll call it level.

line and bar chart

Patterns among prolific robocall signers

Here are robocall and attestation statistics for the top 10 SHAKEN-authorized providers ranked by the percentages of signed calls identified as robocalls.

Prolific robocall signers send many robocalls with A- and B-level attestation

robocalls among calls with A-level attestation are increasing

Figure 6. Robocall Percentage by Attestation—Prolific Robocall Signers by Robocall %

Figure 6 shows robocalls authenticated by prolific robocall signers over the past six months. In March, these robocall percentages were up 1.74% for calls signed with A-level attestation, down 6.04% for calls signed with B-level attestation, and down 3.82% for calls signed with C-level attestation.

We believe that terminating providers should evaluate the reputation of STIR/SHAKEN signers and use it as input to call validation treatment.


  • Overall robocalls were level.
  • SHAKEN participation increased slightly.
  • SHAKEN coverage was level.
  • The percentages of robocalls signed by the top 10 prolific robocall signers were up 1.74% for A-level calls, down 6.04% for B-level calls, and down 3.82% for C-level calls.

TransNexus solutions

TransNexus is a leader in developing innovative software to manage and protect telecommunications networks. The company has over 25 years’ experience in providing telecom software solutions including branded calling, toll fraud prevention, robocall mitigation and prevention, TDoS prevention, analytics, routing, billing support, STIR/SHAKEN and SHAKEN certificate services.

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