STIR/SHAKEN: Why Your Calls Show as 'Spam Likely'

Business calls get marked "Spam Likely" when an analytics engine at the receiving carrier scores the calling number as suspicious. STIR/SHAKEN is the cryptographic signing framework that travels with the call and tells the terminating carrier how confident the originating provider is that the caller owns that number. It feeds the score. It does not set it.

Understanding that split is the difference between fixing the problem and complaining about it. Attestation is about identity. Labeling is about behavior.

What is STIR/SHAKEN and what does it actually do?

STIR/SHAKEN attaches a signed token to a call as it leaves the originating provider's network, asserting who that provider believes is calling.

The originating provider signs. The terminating provider verifies the signature and passes the result to its own analytics. Nothing in the framework decides whether a call is wanted — it establishes only whether the caller ID can be trusted. It exists because caller ID was never authenticated: anyone could present any number, which is what made large-scale spoofing possible.

That is the limitation people misread. A signed, fully attested call from a legitimate business is still a call. If it looks statistically like a robocall campaign, it gets labeled like one.

What do attestation levels A, B, and C mean?

Three levels, describing how much the originating provider knows about the call.

Full attestation is the goal, and getting it is mostly mechanical: present a number that lives on your own account with the provider carrying the call. Presenting a number you own somewhere else — a legacy main line parked at a previous carrier, a personal cell — is what drops a call to B. That is the practical argument for consolidating numbers with whoever carries your calls, and for porting rather than forwarding. Who owns your phone number covers the porting rights side.

Why is my call labeled spam even though I am a legitimate business?

Because attestation is one input among many, and the others are behavioral. Analytics vendors — not the carriers directly — score numbers on patterns, and legitimate businesses generate several of those patterns by accident. The signals that move a score:

• Call velocity. Many outbound calls in a short window reads as a campaign whether or not it is one.
• Short average duration. A run of six-second calls looks like a dialer hanging up on voicemail.
• Low answer rate. If most calls go unanswered, the score assumes people are avoiding you.
• Number age and history. A recycled number inherits the previous holder's reputation, complaints included.
• Consumer reports. Someone tapping "report spam" is a direct, weighted input.
• Caller ID inconsistency. A number that emits outbound traffic but never receives calls, or does not match a known business identity, scores worse.

The last two are where honest offices lose. A clinic dialing from six extensions that each present their own direct number generates six weakly-identified numbers instead of one strong main line. Reputation is sticky, too: a number labeled during a bad month keeps the label after the behavior changes, until something clears it.

How do I get the 'Spam Likely' label removed from my number?

There is no single switch, because there is no single label. Each major mobile carrier uses its own analytics vendor with its own remediation path. The sequence that works:

1. Find out what each carrier actually shows. Test-call a phone on each major network. "Spam Likely," "Scam Likely," and a plain unknown number are different outcomes with different causes.
2. Register your number and business identity with the analytics providers behind the major carriers. Each publishes a free registration and dispute process, and a consortium portal covers several in one submission. Treat any vendor selling a paid guarantee skeptically.
3. File a correction for each carrier showing a label. Expect days, not minutes, and expect to repeat it if the underlying behavior has not changed.
4. Fix the outbound caller ID first, or the correction will not hold.
5. Make the number answerable. A number that receives and answers calls builds a better profile than one that only dials out.
6. Wait. Reputation scores are rolling; improvement shows up over weeks.

Step 4 is the one under your direct control. Set every extension's outbound caller ID to the same main number unless there is a reason not to — one well-identified, frequently-answered number outperforms a dozen thin ones. The outbound caller ID guide covers setting it per extension, and wrong caller ID on outbound calls covers what to do when what you configured is not what recipients see.

Does rotating phone numbers help avoid spam labels?

No. It is the fastest way to make the problem permanent.

The logic that tempts people is understandable: the number is burned, get a new one. What actually happens is that the new number has no history, which analytics engines treat as a risk factor of its own. You have traded a bad reputation for no reputation, and no reputation on a number that immediately starts placing high-volume outbound calls looks exactly like what a spammer does after their last number was burned.

Rotation also destroys the asset. Your number is on vehicle wraps, on Google, in patient charts. Churning it costs inbound calls from people who already had it.

The durable position is the boring one: hold one main number for years, present it consistently, answer it reliably, and register it. Number age is a positive signal, and the only one you acquire by doing nothing. If you are buying now, see adding phone numbers and toll-free or local number.

What this means when you switch providers

A switch is the moment number reputation is most at risk, and the risk comes from the workaround people choose. Porting keeps the history, keeps full attestation possible, and keeps the number your customers already have. Forwarding from an old carrier does the opposite: calls originate on numbers the new provider cannot vouch for, attestation drops, and the label follows. Port instead — it takes two to four weeks and is worth the wait.

Frequently asked questions

What is STIR/SHAKEN and what does it actually do?

It is a signing framework that attaches a verifiable token to a call, asserting that the originating provider believes the caller is entitled to present that number. The terminating carrier verifies it. STIR/SHAKEN authenticates identity only — it makes no judgment about whether a call is wanted.

What do attestation levels A, B, and C mean?

A means the provider has a direct relationship with the caller and confirms their right to that number. B means it knows the customer but cannot confirm the number. C means it is passing along a call it knows nothing about. Presenting a number that lives on your own account is what earns A.

Why is my call labeled spam even though I am a legitimate business?

Labeling runs on behavior, not legitimacy. High call velocity, short average duration, low answer rate, a recycled number carrying a previous holder's complaints, and consumer spam reports all push the score. Legitimate offices trip these routinely, especially when each extension presents a different number.

How do I get the 'Spam Likely' label removed from my number?

Test what each major carrier shows, register your number and business identity with the analytics providers behind them, file a correction per carrier, and fix outbound caller ID so calls present one consistent number. Corrections take days and will not hold if the calling pattern is unchanged.

If your calls are getting labeled and you are not sure whether the cause is caller ID configuration or calling pattern, tell us how your team dials out today. That usually identifies which of the two it is within a few minutes.