STIR/SHAKEN Attestation Levels Explained for Small Businesses

DialSwarm team · October 17, 2026 · 4 min read

What STIR/SHAKEN is, in one paragraph

STIR/SHAKEN is a framework phone carriers use to digitally sign calls, so the receiving carrier can check that the caller ID was not faked. When your phone provider places your call, it attaches a signed statement about how confident it is that you are allowed to use the number shown. That statement is called an attestation. The receiving carrier can use it, along with other signals, when deciding how to display or label the call.

The three attestation levels

There are three levels.

A: full attestation. Your provider knows who you are and has verified that you are authorized to use the calling number. This is the level legitimate businesses want.

B: partial attestation. Your provider knows who you are, but cannot confirm you are authorized to use the specific number. This often happens when you call out using a number you got from a different provider.

C: gateway attestation. The provider is passing along a call it received from somewhere else, such as an international gateway, and cannot vouch for the caller or the number.

A plain-language explanation of the levels is available from TransUnion (TransUnion, attestation levels for STIR/SHAKEN, accessed Oct 17, 2026).

Why your attestation level matters

Carriers and the analytics companies that power spam labels look at many signals when deciding how a call should appear. Attestation is one of them. A call with A attestation tells the receiving side that a known provider vouches for the caller and number. Lower levels give less assurance.

A attestation alone will not guarantee your calls are labeled correctly, but lacking it can make problems harder to fix.

How to get A attestation

You do not grant attestation yourself. Your phone provider decides, after it verifies your business and your right to use the number. The general steps:

1. Use numbers from the provider that places your calls. Numbers bought from one provider and used to call out through another often end up with B attestation.
2. Complete your provider's business profile. This typically includes your legal business name, address, tax or registration details, and an authorized representative. On Twilio, for example, this is done through a Trust Hub business profile (Twilio SHAKEN/STIR onboarding, accessed Oct 17, 2026).
3. Attach your calling numbers to that verified profile.
4. Wait for review. Review times vary by provider. We could not confirm a standard timeframe.
5. Ask your provider to confirm the attestation level your calls receive.

Most providers include this at no extra cost, but check yours.

What STIR/SHAKEN does not do

It is easy to expect too much from attestation. It does not:

• Display your business name. Attestation is about the number's authenticity, not branding.
• Remove spam labels on its own. Analytics companies look at many factors, including call patterns and complaints.
• Make unwanted calls acceptable. If people do not want your calls, attestation will not help. Calling people who agreed to hear from you matters as much as any technical step.
• Replace consent. AI calls still require prior express consent. The FCC confirmed in February 2024 that AI-generated voices are artificial voices under the TCPA (FCC Declaratory Ruling FCC-24-17, accessed Oct 17, 2026).

Other steps that help your calls show up correctly

Attestation works best alongside a few other honest steps:

Free Caller Registry. A free service that sends your numbers to the analytics companies Hiya, First Orion, and TNS. It does not display your name and does not guarantee label removal, but it can help reduce wrong labels (Free Caller Registry, accessed Oct 17, 2026).

CNAM. The caller name, up to 15 characters, that some carriers and landlines show. Request it through your provider. Many mobile phones do not display it.

Branded calling. Paid services that show your name, and sometimes a logo, on supported phones. Hiya Branded Call, for example, starts at $99 per month for 750 calls, or $0.14 per call on pay as you go (Hiya pricing, accessed Oct 17, 2026). Apple's offering is now called Business Caller ID in Apple Business, available in the US. Google Verified Calls was shut down on January 31, 2023, so skip any guide that recommends it.

Good calling habits. Call only people who agreed to be called, keep volume reasonable, honor stop requests, and never rotate numbers to dodge labels. DialSwarm agents never claim to be human and say they're an AI when asked, call only consented leads, and honor stop requests.

Our approach is simple: these steps prove who you are. They are not a way around filters, and nothing here guarantees a label disappears.

DialSwarm bills connected calls only, so unanswered dials don't count. You get 10 free calls with no card, and current plans are on the pricing page.

Questions to ask your phone provider

• What attestation level do my outbound calls currently receive?
• What do I need to submit to get A attestation?
• How long does business verification take?
• Do numbers I ported in from another provider qualify?
• Do you support CNAM updates, and how long do they take to appear?
• Do you offer or partner with branded calling services?

Write the answers down. If your provider cannot tell you your attestation level, that is useful information too.

Attestation and AI calling

If you use an AI agent for calls, the same steps apply. The calls are placed through a phone provider, and that provider's verification of your business and numbers determines attestation. Ask your provider, or your calling platform, how attestation is handled for the numbers you use, and confirm the level your calls receive.

Questions