Why are some calls verified and some aren't?

why are some calls verified and some arent: 3 technical reasons

Understanding why are some calls verified and some arent protects against potential communication risks. Unverified calls indicate potential security vulnerabilities or spoofing attempts. Recognizing these distinctions ensures better digital safety and prevents fraudulent interactions. Learn the underlying reasons to maintain secure connections and avoid risks in daily phone usage.

Why are some calls verified and some aren't?

The short answer is that verified calls have passed a digital identity check called STIR/SHAKEN, proving the caller ID on your screen hasnt been faked or spoofed. Calls remain unverified when they originate from older landline networks, cross international borders, or come from smaller carriers that havent yet modernized their equipment. However, theres one counterintuitive factor that most users overlook: a verified checkmark confirms the callers identity, but it doesnt always guarantee their intentions - Ill explain why are some calls verified and some arent in the security section below.

STIR/SHAKEN - a technical mouthful that essentially means a digital caller ID passport - is the framework making this verification possible. When a call is placed, the originating carrier signs it with a digital certificate. Your own carrier then checks that signature. If the digital keys match, your phone displays a checkmark next to phone number meaning the ID is legitimate. If the chain of trust is broken at any point, the verification fails, and you are left wondering whether to pick up.

The Three Levels of Digital Trust

Not all verified calls are treated equally behind the scenes. Carriers assign one of three attestation levels to every call, which determines whether that checkmark appears. Level A, or Full Attestation, is the gold standard. It means the carrier knows exactly who the customer is and confirms they have the legal right to use that specific phone number. Understanding stir shaken attestation levels explained helps clarify why a high percentage of call traffic between the top seven U.S. carriers is signed and verified, with a vast majority of those calls receiving this top-tier A-level trust. ^[1]

Then there are the lower tiers. Level B (Partial Attestation) means the carrier knows the customer but cant verify if they own the number - often the case with large office buildings using a central phone system. Level C (Gateway Attestation) is the lowest, typically applied to calls entering the network from international sources. In these cases, the carrier can only verify where the call entered their system, not where it truly started. This nuance is why doesn't every call have a checkmark on your device.

The Legacy Tech Gap: Why Verification Fails

If the technology is so effective, why doesnt every legitimate call have a checkmark? The primary hurdle is infrastructure. STIR/SHAKEN relies on IP-based (internet-protocol) networks to carry digital signatures. Older networks (often referred to as TDM or legacy copper-wire systems) simply cannot transmit the kilobytes of data required for a digital signature. While Tier-1 carriers have modernized rapidly, smaller providers are struggling with the transition.

Industry data highlights a massive divide: while major providers are reaching near-universal signing, smaller carriers only sign a small percentage of their call traffic. ^[2] This creates a dark zone for scammers to hide. When a call starts on a modern network but passes through an old-school rural exchange, the verification data is often stripped away. To the recipient, it looks like just another unverified, potentially dangerous call. Its a frustrating gap that leaves millions of legitimate business calls in the same bucket as junk mail.

Does 'Verified' Always Mean the Call is Safe?

Here is the critical factor I mentioned earlier: being Verified only means the caller is who they say they are - it does not mean they are a good person. Scammers are increasingly moving away from simple spoofing and toward legitimate, verified registrations. Recent monitoring data shows that scams actually carry A-level attestation a significant portion of the time in certain monitored datasets. Similarly, regular spam calls are attested at the highest level of trust a substantial percentage of the time. ^[4]

Rarely has a simple checkmark carried so much weight in our daily lives. I used to think the checkmark was a green light to answer, but Ive learned the hard way that identity and intent are two very different things. My own phone once displayed a Verified checkmark for what turned out to be a sophisticated tax scam. The caller wasnt spoofing a number; they had legally registered a business number specifically to bypass the filters. They were verified as a real entity, but their goal was still to steal my data.

The Reality of Neighbor Spoofing and Consumer Trust

Lets be honest: our trust in the phone has hit an all-time low. Most Americans (a majority) simply refuse to answer calls from numbers they dont recognize. When a number is unknown, answer rates plummet to very low levels. This call avoidance epidemic has forced carriers to push for better branding solutions. Without a checkmark, even your local doctors office struggles to reach you. Scammers exploit this by using neighbor spoofing - faking the first six digits of your own number to trick you into thinking its a local neighbor.

The breakthrough in this technology wont just be about checkmarks, but about Branded Caller ID. Soon, instead of just a Verified badge, you might see the company logo and the specific reason for the call, such as Apex Banking - Fraud Alert. For now, the best strategy is how to tell if a phone call is spoofed through a mix of technology and caution. If a call is unverified, it might be a legitimate caller on an old network, but its always safer to let it go to voicemail. If its important, theyll leave a message. You heard that right. Simple, but effective.

Decoding Call Attestation Levels

The STIR/SHAKEN framework uses three levels of 'attestation' to rank how much the carrier trusts the caller's identity.

Level A (Full Attestation) - Recommended

- Carrier knows the customer and confirms they own the phone number being used

- Almost always displays as 'Verified' or with a checkmark on modern smartphones

- Extremely low; proves the number hasn't been hijacked or faked

Level B (Partial Attestation)

- Carrier knows the customer but cannot confirm they are authorized to use the number

- May show a checkmark, but often filtered more aggressively by spam algorithms

- Moderate; common with large PBX systems or centralized corporate hubs

Level C (Gateway Attestation)

- Carrier only knows where the call entered their network (e.g., from an international line)

- Rarely shows a checkmark; often labeled as 'International' or 'Potential Spam'

- High; this is the primary route for overseas scam operations

Sarah's Missed Hospital Call

Sarah, a teacher in Chicago, was waiting for her husband's post-surgery update. When a call appeared from a local 312 area code without a 'Verified' checkmark, she assumed it was a telemarketer and let it go to voicemail.

She spent the next hour in a state of growing anxiety, eyes burning from staring at her silent phone. It turned out the hospital was using an older analog phone system that didn't support STIR/SHAKEN signatures.

The realization hit her when she finally listened to the voicemail: 'This is Mercy Hospital calling with an update.' She felt a wave of guilt for letting technology's lack of a badge dictate her behavior during a family crisis.

Sarah now saves all hospital departments into her contacts. She learned that while verification helps, a missing checkmark doesn't always mean a scam - it often just means the caller is stuck on 20th-century technology.

The 'Verified' Scammer Breakthrough

Minh, a freelance designer in Seattle, received a 'Verified' call that displayed his bank's name. Because of the checkmark, he answered immediately and followed the instructions to 'secure' his compromised account.

The friction came when the caller asked for a one-time passcode. Minh hesitated, realizing that even though the call was verified, the request felt wrong. He hung up and called the bank's official number directly.

He discovered that the scammers had legally registered a business and a similar-looking number to get 'Full Attestation.' The breakthrough was realizing that verification confirms identity, not the person's character.

Minh avoided a $2,500 loss by trusting his gut over the digital badge. He now tells friends that a checkmark is just a passport check, not a background check on the caller's morals.