STIR/SHAKEN statistics from March 2025

The March 2025 STIR/SHAKEN and robocall statistics are now available. The data show the latest trends in robocalls, STIR/SHAKEN participation, and attestation level usage. Let’s have a look.

Signed robocalls by attestation level

Robocalls level at all attestation levels

Figure 1. Signed Robocalls by Attestation Last 6 Months

Figure 1 shows signed robocalls by attestation level over the past six months. The statistics were changed only slightly from February. Robocalls among all calls were down 0.2% from February. Robocalls signed with A-level attestation were down 0.4%. Robocalls among calls signed with B attestation were up 0.7%, while robocalls among calls signed with C attestation were up 0.1%.

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),

Slightly more SHAKEN signers

Figure 2. Monthly Number of OSPs Sending Signed Calls

Figure 2 shows the number of Originating Service Providers (OSPs) observed signing calls in March was up 2.0% from February.

The number of SHAKEN-authorized providers up slightly

Figure 3. STIR/SHAKEN Authorized Providers by Month

Figure 3 shows the number of SHAKEN authorized providers. There was a slight increase of 1.4% in March.

STIR/SHAKEN coverage

Signed calls at termination continues downward trend

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 dropped 1.4% in March, to 41.4%. This continues a gradual decline from the all-time high in October 2024 of 49.3%, a drop of almost 8%.

Signed calls down across all attestation levels

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 27.6% in March, down 0.4% from 28.0% in February. Calls signed with B-level attestation were 3.6%, down slightly from 3.8% in February. Calls signed with C-level attestation were 7.6%, down 0.7% from 8.3% in February. These results reflect the overall decline in signed calls at termination represented in Figure 4.

More calls are being authenticated at origination, yet fewer calls still have this information when they arrive at termination.

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.

Robocalls from prolific robocall signers decreased

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

Figure 6 shows robocalls authenticated by the top 10 robocall signers ranked by robocall percentage over the past six months.

In March, the robocall percentages among prolific robocall signers were down 10.6% across all attestation levels. Robocalls with A-level attestation increased 5.2%. Robocalls with B-level attestation decreased 46.9%. Robocalls with C-level attestation increased 9.0%.

Calls from prolific robocall signers

Figure 7. Call Percentage by Attestation—Prolific Robocall Signers

Figure 7 shows the percentages of calls signed by the top 10 robocall signers by authentication level. They continue to sign their calls mostly with A-level attestation. This is why the robocall percentages are so volatile among B- and C-level calls.

Recap

• Robocalls were level with minor changes from February.
• STIR/SHAKEN participation continues a gradual upward trend.
• STIR/SHAKEN coverage, however, continues a gradual decline from a peak of 49.3% in October 2024 to 41.4% in March 2025.
• We suspect that more calls are being routed across non-IP segments in the call path, where SHAKEN information is lost.
• The percentages of robocalls signed by the top 10 prolific robocall signers were down 10.6% across all attestation levels. These signers continue to sign most calls with A-level attestation.

TransNexus solutions

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

Contact us today to learn more.