Why Your Calls Are Marked Spam – And How to Fix It with STIR/SHAKEN
Your phone is one of the most important devices for your organization. From contacting prospects to receiving customers’ calls, it’s the lifeline of your business operations. If it works fine, you can achieve any objectives you set. If it doesn’t, then everything can come to a standstill.
Nowadays, it’s not uncommon to see the phone numbers of several legitimate businesses marked as spam. Their number flashes on the screen of mobile devices. The name of the business is shown. But just below it, it’s written “Spam Risk” or “Likely Scam.” Why does it happen? Well, there are various reasons behind it. But it can be easily fixed with the help of modern technology.
In this blog post, we will discuss the various reasons behind calls being marked as spam, what are the impacts of calls being marked as spam, and how to prevent calls from being marked as spam. In addition to that, we will also discuss everything about STIR/SHAKEN, how it works, and how to implement it for your business.
If you are worried about your calls being marked as spam or if it has happened to you already, this blog post will assuage all your concerns and will give you valuable tips using which you can bid adieu to your calls being marked as spam for good. Read on and you would thank yourself for doing that.
Top Reasons Behind Calls Being Marked as Spam
As we have already mentioned, many legitimate businesses have their phone numbers marked as spam. There are several reasons behind it and we are going to discuss some of the most common ones here.
1. High volume of outgoing calls
If an organization, no matter how reputable or trustworthy, makes a huge volume of outbound calls from the same number, then the likelihood of its calls getting flagged as spam increases. That’s the reason even calls from legitimate sources get flagged as spam. This is a common problem for call centers and contact centers as they try too many calls. It gets worse if the answer rates and contact rates are low.
2. Short duration of calls, high missed calls or hang ups
Frequent short-duration calls, as well as hang-ups or missed calls, can get their phone numbers marked as spam. It can signal poor calling behavior to carriers and spam filters.
3. Calls made outside normal business hours
Not all calls made outside normal business hours are nuisance calls or unwanted calls. On the contrary, it could be important calls from legitimate businesses that operate in different time zones. For instance, you have logged into your Google account and the company calls you to verify it’s you. But it would be terrifying if it’s marked as spam. Similarly, you get a call from a reputable company for some legal requirement. What would be the scenario if the call is flagged as spam?
4. The rise of robocalls and spoofing
As per latest data the first five months of 2025 have witnessed 23.8 billion robocalls. In terms of year-on-year growth, it’s 11 percent. The increase in robocalls, spam calls and fraudulent calls has eroded trust in phone calls. To deceive unsuspecting people, scammers often spoof a local area code or the same number as the recipient. As a result, many legitimate businesses get caught in the crossfire and get their calls getting flagged as spam.
5. Role of carriers and apps
Carriers and spam call detection apps such as Hiya, TNS, and Truecaller use algorithms and spam detection systems. They also use reputational analytics to determine whether or not a call is spam. Even though the accuracy of their systems and analytics are high, they are not 100 percent error proof. Some patterns such as too many calls or short calls can trigger spam filters and mark calls from legitimate businesses as spam.
6. Inaccurate or incomplete caller ID
If businesses have not entered accurate details in their caller ID or they have left their IDs incomplete, then it puts them at the risk of having their numbers flagged as spam. Apart from inaccurate caller ID and incomplete id information, missing asserted information can lead to phone numbers being flagged as spam.
Key Impacts of Calls Being Marked as Spam
While it’s not uncommon for legitimate businesses to get their phone numbers flagged as spam, the impact can be detrimental to their businesses. When an average person sees a number being flagged as spam, then chances of not receiving the call is extremely high. It doesn’t matter who is calling or where the call is coming from. The spam alert is alarming enough to make the person decline the call. Let’s look at some key impacts of calls being marked as spam.
1. No answer
When a business’s phone number is flagged as spam, answer rates, calls answered, and overall contact rates drop sharply. No matter how many times it calls its customers, it gets no answer.
2. Damaged brand reputation
Please be honest. Would you trust the organization if you see their calls flagged as spam? Certainly not. Spam tags damage legitimate businesses. Once spam labels are displayed below the number of any business, the reputation is gone. Nothing impacts trust like the suspicious caller ID information.
3. Lost revenue opportunities
When calls are marked spam, outbound calls from a call center don’t connect, resulting in lost leads and sales. Every missed call reduces revenue potential. Fewer responses from customers and consumers mean each phone number and rep effort is less productive.
4. Increased customer complaints
When customers see calls with spam labels and spam tags, they don’t receive it. However, if the calls keep on coming repeatedly, they report them as unwanted calls, nuisance calls, and fraudulent calls. If the customer complaints escalate, it can blacklist the flagged numbers.
5. Lower contact center efficiency
Spam flags and spam marks can reduce call center productivity. That’s quite natural when a contact center makes high volumes of outbound calls but very few people answer the calls. Inconsistent response patterns impact metrics and overall performance.
How to Prevent Calls from Being Marked as Spam
As already discussed, businesses can easily prevent their calls from being flagged as spam (or put their phone numbers off from the spam list) by leveraging the right technology tools and adopting some simple strategies. Here are some effective ways using which businesses can do that.
1. Comply with STIR/SHAKEN framework
The most effective way businesses can prevent their calls from being marked as spam is by complying with the STIR/SHAKEN framework. We will discuss more about the STIR/SHAKEN framework in the next section.
2. Use proper caller ID and consistent business information
Businesses must ensure that their caller ID is accurate and aligned with their brand. Using a consistent calling party name is a great way to start. They should also avoid changing the same number across campaigns.
3. Maintain optimal call volume
Businesses can prevent their calls from being marked as spam by ensuring that their outbound call volume remains within acceptable limits. Businesses should avoid high call volumes as much as possible.
4. Avoid aggressive dialing patterns
Aggressive dialing patterns are often associated with predictive dialers. There’s nothing wrong with dialing multiple numbers simultaneously and waiting for customers to pick up the calls. But if the abandonment rates are high, then it increases the risks of calls being flagged as spam.
5. Monitor number reputation
Businesses must use reputational analytics to monitor the reputation of their phone numbers. They must respond to spam labels and scam-related issues fast using insights from reputational analytics.
What Is STIR/SHAKEN?
| STIR stands for Secure Telephone Identity Revisited. SHAKEN stands for Signature-based Handling of Asserted information using toKENs. |
How Does STIR/SHAKEN Work?
STIR checks if the caller is really who they say they are. When an organization places a call, the phone carrier checks to determine if it owns the phone number and is it allowed to use it? If yes, it gives the call one attestation level of the three:
Full (A): It’s the highest level. It means that the business owns the number and its identity is verified.
Partial (B): Mostly sure but not completely. The number is known but may not be fully verified.
Gateway (C): It’s the lowest level. The carrier passes the call but can’t verify the number.
After giving the attestation level, the carrier digitally signs the call. As the call reaches the receiving phone network, the digital certificate is verified.
If it doesn’t match, the call is likely to be marked spam.
Based on Session Initiation Protocol (SIP), SHAKEN is designed to work with calls being routed through a VoIP network.
It uses the name tags to help phone companies decide if they should trust the call or not. Just similar to a special code for phone calls to ensure they’re from the right person.
If the tag is good, the call goes through. If it looks dubious, it might show a warning or not ring at all.
How to Implement STIR/SHAKEN for Your Business?
When it comes to implementing the STIR/SHAKEN framework for your business, following some best practices can make a lot of difference. Here are some ways you can implement STIR/SHAKEN for your business.
1. Choose the right IP PBX or telecom provider
First of all, check whether or not your voice provider supports STIR/SHAKEN. If not, then you would be better off switching to a IP PBX or telecom provider that has fully integrated STIR/SHAKEN at the network level. Look for a reputable and trustworthy solutions provider that knows the ropes and works closely with carriers.
2. Integrate with your SIP or VoIP infrastructure
The next thing you must do is to integrate the IP PBX software with your SIP or Voice over Internet Protocol (VoIP) infrastructure. That would ensure your system handles outbound calls well. It also ensures correct caller ID information, phone numbers, and caller details.
3. Use branded information
Some telecom and IP PBX solutions providers enable you to add your business’s logo, company name, as well as the reason for calling to the display on the recipient’s phone. The whitelabeling feature can help in preventing (even fixing) calls being flagged as spam.
4. Assign proper attestation levels to calls
Label your calls right. Use the right attestation level to verify the caller’s identity and give carriers trust. This helps legitimate businesses boost contact rates. Also, watch your calls and look for spam labels, flagged calls, and calls marked as spam.
5. Monitor call reputation and comply with regulations
Last but not least; use reputational analytics to monitor your outgoing calls. Use tools such as Hiya, TNS, and others to track how your numbers are perceived. Comply with all domestic and international regulations. Avoid calling numbers on Do Not Call (DNC) lists.
Final Words,
Spam labels can seriously damage your business’s ability to connect with customers. However, the advent of STIR/SHAKEN has proven to be a boon for all types and sizes of businesses. It’s a powerful tool to verify their caller ID information and reduce the risk of being flagged as spam.
You must ensure that your telecom or IP PBX solution provider supports the STIR/SHAKEN framework. If not, then it’s prudent to look for the right IP PBX software that implements STIR/SHAKEN protocols.
At HoduSoft, we know the role STIR/SHAKEN protocol plays in fixing calls from being marked as spam. We have engineered our HoduPBX IP PBX software that’s compliant with the STIR/SHAKEN framework. If you are curious to know more about our STIR/SHAKEN framework compliant IP PBX software, contact us today to get a free demo.
