STIR/SHAKEN statistics from March 2026

March 2026 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 down across 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. Overall, the statistics were down from February across all attestation levels. Robocalls among all calls were down 1.1%. Robocalls signed with A-level attestation were down 0.2%. Robocalls among calls signed with B attestation were down 1.0%. Robocalls among calls signed with C attestation were down 0.9%.

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).

The number of SHAKEN signers decreased

Figure 2. Monthly Number of OSPs Sending Signed Calls

Figure 2 shows that the number of Originating Service Providers (OSPs) observed signing calls in March was down 13.5% from the previous month, a surprising decrease.

The number of SHAKEN-authorized providers increased

Figure 3. STIR/SHAKEN Authorized Providers by Month

Figure 3 shows that the number of SHAKEN-authorized providers in March was up 3.8% from the previous month.

STIR/SHAKEN coverage

Signed calls at termination down again

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 was down 1.8% in March, to 42.7%.

We see continued trends with the number of SHAKEN-authorized providers increasing while the percentage of signed calls received at termination drops. We believe that this statistic reflects calls being routed over non-IP segments in the call path, where the SHAKEN call authentication information is lost.

A-level attestation down

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

Figure 5 shows the percentage of calls signed by attestation level. The percentage of calls signed with full A-level attestation was 27.8% in March, down 0.7% from February. The percentage of calls signed with B-level attestation was 3.5%, down 0.5% from February. The percentage of calls signed with C-level attestation was 7.5%, down 1.5% from February.

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 down

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 percentage among prolific robocall signers was down 1.0% across all attestation levels. The robocall percentage with A-level attestation was down 1.6%. The robocall percentage with B-level attestation was up 1.0%. The percentage of robocalls with C-level attestation was up 1.0%.

Prolific robocall signers authenticate most calls with A-level attestation

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. In March, 89.8% of the calls authenticated by prolific robocall signers had an A-level attestation. 9.4% had a B-level attestation. Almost none had a C-level attestation.

Recap

• Robocalls were down from February.
• STIR/SHAKEN participation went in two different directions, with 13.5% fewer SHAKEN signers yet 3.8% more authorized providers.
• STIR/SHAKEN coverage dropped 1.8%, to 42.7%.
• Robocalls authenticated by prolific robocall signers dropped 1.0%. They signed 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.