STIR/SHAKEN statistics from June 2025

June 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 up slightly

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 up slightly from May. Robocalls among all calls were up 0.2% from May. Robocalls signed with A-level attestation were up 0.2%. Robocalls among calls signed with B attestation were up 0.2%, while robocalls among calls signed with C attestation were up 1.2%.

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 up

Figure 2. Monthly Number of OSPs Sending Signed Calls

Figure 2 shows the number of Originating Service Providers (OSPs) observed signing calls in June was up 7.7% from May.

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 was up 8.1% in June, reaching an all-time high of 1,606.

The increase in SHAKEN-authorized providers and signers observed authenticating calls is a result of the FCC order that providers with a SHAKEN obligation must either sign their calls or have their calls signed for them by a signing service using their own SHAKEN certificate and determination of attestation level.

STIR/SHAKEN coverage

Signed calls at termination down

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 1.9% in June, to 40.4%. This statistic has been on a downward trend since October 2024, when it peaked at 49.3%.

We believe that this statistic remains low because of non-IP segments in the service provider voice network. Despite a healthy jump in the number of signers authenticating calls, an even greater portion of call authentication information was lost when calls were routed over non-IP segments in the call path.

We believe that the FCC’s proposed rules to mandate non-IP call authentication methods for providers that rely on non-IP networks is the only remedy for this problem. This mandate would force providers to either transition to IP networks or implement non-IP call authentication mechanisms.

Signed calls level across 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 27.4% in June, down 1.4% from May. Calls signed with B-level attestation were 3.2%, down 0.2% from May. Calls signed with C-level attestation were 7.2%, down 0.1% from May.

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 increased

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 June, the robocall percentage among prolific robocall signers was up 1.8% across all attestation levels. Robocalls with A-level attestation were down 1.1%. Robocalls with B-level attestation were up 27.4%. Robocalls with C-level attestation decreased 4.1%.

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. In June, 94.5% of the calls authenticated by prolific robocall signers had an A-level attestation.

We encourage terminating service providers and call analytics providers to incorporate SHAKEN signer reputation into their call analytics. We provided examples in a blog post, How to monitor SHAKEN signer reputation.

Recap

• Robocalls were up slightly from May.
• There was a healthy increase in STIR/SHAKEN participation in May due to the pending rules that require providers that claim a STIR/SHAKEN implementation to use their own SHAKEN certificate and determination of attestation level.
• STIR/SHAKEN coverage has been in steady decline since October 2024. In June, only 40.4% of calls arrive at termination with call authentication information intact. This is way too low for STIR/SHAKEN to be effective.
  • We suspect that many calls are being routed across non-IP segments in the call path, where SHAKEN information is lost.
• The percentage of robocalls signed by the top 10 prolific robocall signers was up 1.8% across all attestation levels. These signers continue to authenticate 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.