# Spam label glossary

Plain definitions of the terms you'll run into when your calls show as spam. Each links to a fuller guide where one exists.

## Labels you'll see

**Spam Likely**
The everyday term people use for any spam warning on an incoming call. As a specific label, carrier documentation associates it with Spectrum, not the three major wireless carriers, each of which uses its own wording.

**Spam Risk / Fraud Risk (AT&T)**
AT&T's labels, from its ActiveArmor call protection. "Spam Risk" calls ring with a warning, sometimes with a category. "Fraud Risk" calls are blocked automatically and don't ring. [AT&T guide](/guides/remove-spam-label-att)

**Potential Spam / Potential Fraud / Robo caller / SPAM? (Verizon)**
The labels Verizon says it uses for spam calls. [Verizon guide](/guides/remove-spam-label-verizon)

**Scam Likely (T-Mobile)**
T-Mobile's label for calls its network flags as likely scams. It's on by default for all T-Mobile customers. [T-Mobile guide](/guides/remove-scam-likely-tmobile)

**Suspected spam caller (Android)**
The warning Google's Phone app shows on Android phones when it judges a call likely spam. It comes from the phone's built-in caller ID and spam protection, which is on by default, not from the carrier, so it can appear on any carrier.

## Who decides

**Analytics engine (call analytics provider)**
A company that scores calls and supplies spam labels to carriers. The big three in the US are Hiya, TNS and First Orion. [Why numbers get flagged](/guides/why-number-shows-spam-likely)

**Hiya**
The analytics company that supplies AT&T's spam labels. Also powers Samsung's Smart Call.

**TNS (Transaction Network Services)**
The analytics company carrier help documentation identifies behind Verizon's labels.

**First Orion**
The analytics company behind T-Mobile's "Scam Likely" labels.

**Reasonable analytics**
The FCC's standard for when carriers may block calls they judge unwanted. The FCC's examples included large bursts of calls in a short time, low average call duration and low call-completion rates.

## Caller ID and identity

**Caller name (CNAM)**
The name shown with your number on an incoming call. It's separate from spam labels: a clean number can still show no name or an outdated one. Your phone provider sets it.

**Branded calling**
Paid services that show a verified business name, and sometimes a logo or call reason, on the recipient's screen.

**Rich Call Data (RCD)**
A standard for sending verified caller identity information, such as name, logo and call reason, with a call. In October 2025 the FCC proposed requiring verified caller name information under the STIR/SHAKEN framework, potentially using RCD.

**STIR/SHAKEN**
The framework carriers use to digitally sign calls and confirm the caller is authorized to use the number. It doesn't apply spam labels itself, but analytics engines treat it as one input.

**Attestation (A, B, C)**
The level of confidence in a STIR/SHAKEN-signed call. "A" (full) means the provider knows the customer and confirms they're authorized to use the number. "B" (partial) means the customer is known but the number isn't verified. "C" (gateway) means the call entered the network from a source the provider can't vouch for.

**Spoofing**
Faking the number shown on caller ID. When scammers spoof a real business's number, the people they call may report or block it, damaging that number's reputation. "Neighbor spoofing" uses numbers that look local to the recipient.

## Blocking and error codes

**SIP 603+ ("Network Blocked")**
Since March 25, 2026, the code US providers must return when they block a call based on analytics. It includes contact details for requesting a review. [SIP guide](/guides/sip-603-plus-608-network-blocked)

**SIP 608 ("Rejected")**
A code defined in RFC 8688 for calls rejected by an intermediary such as an analytics engine. For US analytics-based blocking, 603+ has replaced it.

**SIP 607 ("Unwanted")**
A code meaning the person called, or blocking they set up themselves, rejected the call.

**ISUP cause 21**
The equivalent blocking signal on older (non-IP) phone networks.

**Do Not Originate (DNO)**
Lists of numbers that should never place outgoing calls, such as inbound-only lines. The FCC's 2025 order requires all voice providers in the call path to block calls from numbers on a reasonable DNO list.

## Fixing labels

**Remediation (review request)**
Asking an analytics provider or carrier to re-evaluate a label. It doesn't guarantee removal, and reviews commonly take days to weeks.

**Number registration**
Registering your business numbers with analytics companies so they know who's calling. Free with Hiya and First Orion directly, or through the Free Caller Registry.

**Free Caller Registry**
A free, single form run by First Orion, Hiya and TNS that sends your number details to all three. [Free Caller Registry guide](/guides/free-caller-registry)

**Number maturity**
How established a number's calling history is. Hiya treats numbers with little or no history as a possible red flag.

## Numbers and rules

**Recycled (reassigned) number**
A number given to a new customer after its previous owner disconnected it. FCC rules require disconnected numbers to sit unassigned for at least 45 days first. A previous owner's history can follow the number. [New-number checklist](/guides/check-new-number-before-dialer)

**National Do Not Call Registry**
The FTC's list of numbers telemarketers generally may not call. Exceptions include established business relationships, such as calling past customers for up to 18 months or following up on an inquiry within 3 months.

**TCPA (Telephone Consumer Protection Act)**
The federal law governing telemarketing and automated calls. Calls using an artificial or prerecorded voice, including AI-generated voices under a February 2024 FCC ruling, generally require the recipient's prior express consent.

**TRACED Act**
The 2019 federal law that required carriers to implement STIR/SHAKEN and directed the FCC to set rules for transparency and redress when calls are blocked.

## Sources

- [Google: Use caller ID & spam protection](https://support.google.com/phoneapp/answer/3459196?hl=en)
- [AT&T ActiveArmor terms of service](https://www.att.com/activearmormseula)
- [Verizon voice spam feedback](https://voicespamfeedback.com/vsf/)
- [T-Mobile: Scam Shield FAQ (Metro by T-Mobile)](https://www.metropcs.com/nameid-faqs.html)
- [Zoho Voice: Whitelisting your phone numbers (US)](https://help.zoho.com/portal/en/kb/zoho-voice/setup/articles/whitelisting-your-phone-numbers-us-only)
- [CXDO: Removal from robocall analytics](https://cxdo.helpjuice.com/en_US/how-to-guides/removalfromrobocallanalytics)
- [ACA International: Summary of FCC 2019 declaratory ruling](https://policymakers.acainternational.org/wp-content/uploads/2020/09/concerns-regarding-fcc-call-blocking-and-labeling-efforts-declaratory-ruling-and-fnprm-may-2019.pdf)
- [Mintz: FCC proposes call branding and caller ID rules](https://www.mintz.com/insights-center/viewpoints/2776/2025-11-20-fcc-proposes-new-rules-call-branding-and-caller-id)
- [Commsrisk: STIR/SHAKEN and analytics](https://commsrisk.com/?p=40001)
- [TNS: How legitimate business calls become "Spam Likely"](https://tnsi.com/?p=27340)
- [RFC 8688](https://www.rfc-editor.org/rfc/rfc8688.html)
- [Telecom Law Partners: Eighth Robocall R&O](https://www.tlp.law/2025/03/26/fcc-publishes-eighth-robocall-ro-in-federal-register/)
- [TransNexus: SIP 603+ effective date set](https://transnexus.com/blog/2025/sip-603-plus-rule-effective-date-set/)
- [Hiya Connect: Caller reputation and spam label help](https://connect-support.hiya.com/hc/en-us/articles/54311390207891-Caller-reputation-and-spam-label-help)
- [NANPA: 45-day minimum aging reminder](https://nanpa.com/sites/default/files/2024-07/NANPA_45_Day_Min%20Aging_Reminder.pdf)
- [Oregon REALTORS®: Do Not Call rules](https://oregonrealtors.org/?p=22627)
- [TransNexus: FCC ruling on AI-generated voice calls](https://transnexus.com/blog/2024/ai-voice-calls-and-tcpa/)
- [First Orion: FreeCallerRegistry.com launch (TRACED Act and STIR/SHAKEN)](https://firstorion.com/?p=10094)
- [46 Labs: SIP 603+ and the TRACED Act redress mandate](https://support.46labs.com/support/solutions/articles/156000380807-2026-updates-communications-service-provider-csp-platform)