Why is my phone number showing up as spam? Common causes and fixes

Every cell phone owner is grateful for the “POTENTIAL SPAM” flag on unwanted incoming calls. There’s far too much spam in the world — the label makes it easier to weed out calls from bad actors.

But for business owners, having your number flagged as spam can be really frustrating. Whether you’ve witnessed it yourself or your customers have informed you about a spam label, it’s a major concern. People likely won’t answer when they see “Scam Likely” or “Spam Risk” appear next to an incoming call, making it harder for you to reach them.

You can take steps if your number has been flagged as “scam likely,” and we’ll explain why it happens and how to fix it.

How does spam labeling impact your business? 

When your number is mistakenly marked as spam, it can have serious consequences for your business: 

• Lost revenue from unanswered calls. When customers don’t pick up because they see a spam label, you miss opportunities for sales, appointments, and time-sensitve questions. 
• Reduced customer trust. Even if customers eventually realize the spam label was a mistake, seeing your business number flagged as “Scam Likely” can create doubt. Customers may wonder if your business is legitimate and professional.
• Interrupted customer service. When existing clients can’t reach you or hesitate to answer your callbacks, it disrupts customer support and creates frustration on both sides.

How a number gets flagged as spam

Your business number can get flagged as spam in several ways — even if you’re a legitimate business.

At a high level, each carrier has an ‘analytics engine,’ which has a constantly evolving algorithm. This system detects if a call should be marked as spam or not. These algorithms and databases aren’t transparent, partly to prevent actual spammers from gaming the system. They are also continuously updated as scammers find loopholes. 

Understanding the causes of your number showing up as spam helps you prevent and fix the problem:

1. Consumers marking calls as spam

When someone receives a call from your business number, they can flag it as spam directly from their phone. They might not recognize your business name, be frustrated by sales calls, or simply be having a bad day. Carriers weigh these manual reports heavily in their algorithms, especially if enough people mark your call as unwanted.

Third-party apps like Truecaller, Hiya, and RoboKiller amplify this problem through crowd-sourced databases. When one user marks your number as spam in these apps, it can affect how your calls appear to millions of other users. These services also share data with carriers, multiplying the impact of individual spam reports.

2. Failed caller ID verification

STIR/SHAKEN, a system for identifying callers, was added onto carriers’ algorithms in 2021 under requirements from the Federal Communications Commission or FCC. The goal was to protect US citizens against unwanted calls — mostly robocalls — which were a top consumer complaint. 

Under the STIR/SHAKEN framework, cell carriers like Verizon and T-Mobile are required to flag calls when the caller ID doesn’t match the caller’s real number. Sometimes, the call might be blocked altogether. In other cases, the call may be flagged as “Possible Scam,” “Spam Likely,” or “Possible Robocall.”

3. Spam history with the phone number

The previous owner of your phone number may have had a history of spam with the carrier. If that’s the case, you can try some of the solutions in this article to remove the mistaken spam label.

4. Phone number spoofing

Bad actors may be using your number for spam or robocalls, making it appear that the calls are from your virtual number, even though they aren’t. This is unlikely but possible. 

5. Call behavior patterns

Carriers use advanced algorithms to analyze phone calling patterns against databases that contain known spam numbers, scam operations, and telemarketers. Certain calling patterns can get flagged as spam:

• A caller dials the same number multiple times consecutively or calls too many times on the same day 
• A caller makes many short calls that are only a few seconds long
• A large spike in volume, like 100 calls within an hour from a single phone number
• A high number of calls go straight to voicemail

How to avoid getting marked as spam and reach customers effectively

Though call carriers created spam filters with good intentions, they can impact lawful businesses. Spam detection and the criteria carriers use aren’t 100% accurate. 

Inaccurate spam/scam labeling affects the entire phone industry and isn’t limited to a single provider. This includes Quo, formerly OpenPhone. Combating incorrect spam labels is an ongoing challenge as carriers continue to intensify their efforts to block spam calls.

Even more frustrating: there’s no one-time quick fix. There are only things you can do to lower the chances your business phone number gets marked as spam.

We’ve got a checklist of a few things you can do:

• Register your phone number with the Free Caller Registry
• Register your phone number with STIR/SHAKEN

• Register your phone number with major carriers

• Configure your caller ID name

• Stay compliant

• Be consistent with your calling behavior

• Reach out to spam-blocking services
• Monitor your phone number’s reputation

Register your phone number with the Free Caller Registry

The Free Caller Registry allows business owners to inform carriers that a phone number has a new owner. This can solve the problem of a previous owner’s bad reputation if the previous owner was engaging in spam-like behavior. 

When you get a US phone number, you can register your number on the Free Caller Registry’s website or have your phone provider do it for you.

When you register, you need to fill out two sections:

1. Calling Company: This is your business information, including the numbers you’re calling from, the company name, and the company address. You’ll also select a type of call, such as “Financial Services” or “Informational.” If your calls don’t fit into any of the categories, select “Other.”
2. Service Provider: Add your business phone provider. If you’re a Quo customer, for example, this would be Quo.

You can also add the number of calls you make per month and identify if your phone numbers have been labeled incorrectly. 

If you also want to text customers in the US with a virtual phone provider, you’ll need to complete US carrier registration. This helps you comply with A2P 10DLC guidelines. You need to follow these rules if you’re calling from local phone numbers. The process is different for toll-free numbers.

Note: Quo users who complete US carrier registration after July 16, 2025 don’t need to register with The Free Caller Registry, since Quo will register your numbers for you.

Register your phone number with STIR/SHAKEN

Registering your phone number with STIR/SHAKEN won’t remove a spam/scam label, but it may increase answer rates from your customers.

The registration process varies by business phone provider. If you’re a Quo customer, all you have to do is complete the Low Volume Standard US carrier registration form. Quo will then automatically register you with STIR/SHAKEN. We’ll also automatically apply your verified business profile to all numbers associated with your Quo account.

During your registration, we also ask you to share your estimated daily call volume. You’ll need to enter an estimate of your total daily incoming and outgoing calls you expect to receive on all Quo numbers. We ask you to share this information so that we can provide it to industry partners that can assist with reducing the likelihood that your calls are marked as ‘Spam/Scam Likely’.

What if I’m calling someone in Canada?

STIR/SHAKEN regulations don’t apply to Canadian numbers. There isn’t a standardized framework like there is in the US for registering numbers to prevent spam labeling.

One way you can prevent spam labeling in Canada is by registering with Hiya.

Register your phone number with major carriers

If you’ve registered your number with the Free Caller Registry and STIR/SHAKEN and carriers are still mistakenly flagging your calls as spam, you can take some additional steps. Registering directly with carriers is free and can increase your number’s reputation and ensure that carrier records are up-to-date.

Here’s how you can register with each:

• T-Mobile: Fill out the First Orion form or contact [email protected]
• Verizon: Fill out this form or directly contact [email protected]
• AT&T: Fill out the Hiya form or directly contact [email protected]

Configure caller ID

CNAM is the Caller ID Name and displays the caller’s name on the recipient’s phone, which can even be a business caller ID. CNAM was originally intended for landline numbers and rarely works with mobile devices. When it does work, it’s often outdated, which leads to incorrect caller ID displays. 

In the US, T-Mobile is the only carrier that provides CNAM lookup at no extra cost. T-Mobile customers can view caller IDs for incoming calls. For all other carriers, this feature comes with an additional fee. 

Configuring your CNAM won’t remove a spam label, but it may increase your answer rates since people are more likely to answer if they can identify the caller. Since a high volume of calls going to voicemail is a signal to phone carriers that a number might be spam, this can help your number’s overall reputation.

Note: Quo customers can complete self-service CNAM registration in their workspace. A2P Low Volume Standard registration and approval is a prerequisite to CNAM registration.

Stay compliant

Registered numbers can still be flagged if consumers report your calls as spam to the FCC or in a fraud report.

Follow all relevant laws, regulations, and policies — including your phone provider’s Terms of Service. All callers must stay compliant, whether they’re VoIP callers, using WiFi calling, or calling from a traditional landline. 

Here are a few things you should do:

• Follow the Telephone Consumer Protection Act, which requires you to adhere to all “Do Not Call” lists and TCPA opt-in/opt-out requirements for business texts. 
• Clearly identify your business when calling and give call recipients simple instructions for opting out of future calls.
• Create dedicated phone numbers for specific call functions, such as customer support or surveys, especially if you run outbound call campaigns. 

Be consistent with your calling behavior

If there’s a sudden spike in your outbound call patterns, your phone number can be flagged as spam — even if it’s registered. 

Even though we don’t know the specifics of carrier algorithms that identify spam, some calling patterns can raise red flags. The more consistent you are, the less likely this will happen to you. 

Here are some effective strategies:

• Maintain regular outbound call volume with no unusual spikes. If you plan to ramp up your call volume, do it gradually instead of hitting your full target call volume at the start of a new campaign. 
• Update your calling lists regularly and remove numbers that don’t connect. Low call answer and completion rates are associated with spam, so you want to avoid dialing random or sunset numbers.
• Prioritize calls to customers with whom you have an established business relationship rather than making broad, unsolicited outbound calls. Customers who expect your calls are more likely to answer.
• Use distinct phone numbers for functions like marketing, surveys, and customer support callbacks. Distinct phone numbers help you manage customer expectations. You don’t want receivers to be confused or suspicious when they answer.
• Make calls during standard business hours to align with expected communication norms. Calling outside of business hours won’t make the best first impression.

Reach out to spam-blocking services

If you’ve done everything above and you’re still having issues with your calls being flagged as spam, you can try contacting spam-blocking apps. These apps may be installed directly on customers’ phones to block unwanted calls. 

Here are some common spam-blocking apps and their contact information:

• Robokiller: Email [email protected]
• Nomorobo: Email [email protected]
• IceHook: Contact at https://www.icehook.com/contact
• TrueSpam: Contact Info at https://www.truecnam.com/contact_us

Monitor your number’s reputation

By regularly monitoring how your business number appears to recipients, you can catch spam flags early. One easy way to do this is by making test calls to colleagues or friends who use different carriers like AT&T, T-Mobile, or Verizon. Ask them to screenshot how your incoming call appears. 

You can check your call logs or CRM history for patterns like unusually high rates of unanswered calls. This could indicate your number is being flagged. You can also enter your number on free apps like Truecaller to see reported spam statistics.

As a last resort, you can use a service like Caller ID Reputation. These third-party services can check if your number is showing up as spam for different carriers and spam-blocking apps. Then, they remediate the spam labels on your behalf.

Give customers a better experience with Quo

Your small business should do everything it can to maintain a professional phone reputation. This creates a better experience for your customers and reduces the risk of your phone number getting flagged as spam. 

Within Quo, you can complete your US carrier registration. Quo also helps you maintain a professional presence through features like: 

• Voicemail greetings 
• Auto-replies to missed calls, texts, and voicemails
• Conditional call forwarding to redirect unanswered calls to another person
• Ability to share a business phone number with your team

Quo also gives you clarity around your call activity. You can see if customers abandoned a call or if call avoidance is occurring. If needed, you can quickly review calls with AI-generated transcripts and summaries.

See if Quo is the right fit for your team with a free seven-day trial.
If you’re already a Quo customer and have additional questions about registering your number, you can submit a support request here.

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