STIR/SHAKEN statistics from February 2025

The February 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 at lower attestation levels

Figure 1. Signed Robocalls by Attestation Last 6 Months

Figure 1 shows signed robocalls by attestation level over the past six months. Robocalls among all calls were up 0.6% from January, as were robocalls signed with A-level attestation. Robocalls among calls signed with B attestation were up 2.6%, while robocalls among calls signed with C attestation were up 3.7%.

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 February was up 2.6% from January.

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 1.8% in February.

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 2.5% in February, to 42.8%. This continues a gradual decline from October 2024.

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 28.0% in February, down 1.3% from 29.3% in January. Calls signed with B-level attestation were 3.8%, down slightly from 4.2% in January. Calls signed with C-level attestation were 8.3%, down 0.6% from 8.9% in January. These results reflect the overall decline in signed calls at termination represented in Figure 4.

So, participation is increasing, yet coverage is decreasing. More providers are authorized and signing calls, yet fewer signed calls arrive at termination. Why?

Our first thought is that this might be from an increase in call routing across non-IP segments in the middle of the call path. More calls are being authenticated at origination, yet fewer calls still have this information when they arrive at termination. The non-IP segments stripped the SHAKEN information from the calls.

We described this issue in our recent blog post, New Out-of-Band SHAKEN standard published. This problem will remain until either the non-IP segments are replaced with SIP interconnections or transit providers begin using non-IP call authentication solutions, such as Out-of-Band SHAKEN.

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 February, the robocall percentages among prolific robocall signers were up 15.9% across all attestation levels. Robocalls with A-level attestation increased 12.0%. Robocalls with B-level attestation increased 47.7%. Very few calls are signed by prolific robocall signers with C-level attestation, and this group of calls includes very few robocalls.

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. However, there was a shift in the percentages among attestation levels. Calls signed with A-level attestation dropped 6.5%, and calls signed with C-level attestation dropped 3.3% from January. Calls signed with B-level attestation increased 9.8%.

Recap

• Robocalls were up slightly overall. Robocalls signed with B-level attestation were up 2.6%, while robocalls signed with C-level attestation were up 3.7%.
• STIR/SHAKEN participation was up slightly.
• STIR/SHAKEN coverage continues a gradual decline from a peak of 49.3% in October 2024 to 42.8% in February 2025.
• The combination of increasing participation yet decreasing coverage suggests 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 up an average of 15.9% across all attestation levels. These signers continue to sign most calls with A-level attestation. However, there was a 6.5% drop in A-level calls and a 3.3% drop in C-level calls, with a corresponding increase of 9.8% going to B-level calls.

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.

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