5 minute read |

How to Easily Block VoIP Calls

VoIP phone service background

At this point, there is no doubt that VoIP is the future of voice communication. Even though some people and companies continue to use the PSTN, it won’t be around much longer. Telephone carriers in many countries around the world have already discussed ending support for the PSTN over the next decade. So why are a few companies still holding out against VoIP phone services? 

VoIP is a digital technology, it offers many more useful features that are suited to the modern business world than analog landlines. It also brings down the cost of enterprise phone systems substantially.  

At the same time, it’s not as if VoIP doesn’t have any drawbacks. For one thing, it needs the internet and power to function. So you need to have backup options to keep the phones working during an emergency. Sometimes, people and companies are not sure how to enable a particular feature on their VoIP systems. So they hesitate to upgrade. 

Why Block VoIP Calls? 

One such feature is blocking VoIP calls. You can find a lot of information online about routing calls and managing them effectively within a business. But there is not much information on how to combat VoIP spam. 

We are all familiar with unwanted calls. As consumers, there is nothing more annoying than being interrupted multiple times throughout the day. But that’s exactly what happens to most people and businesses on a typical day. Unwanted calls can be anything from scammers to unscrupulous telemarketers.  

Reduce Interruptions 

The biggest reason you want to block VoIP calls – specifically unwanted ones – is to eliminate interruptions. If you have a sales team or support team, the phone lines shouldn’t be tied up from spammers! You want your customers to be able to reach you. But if a significant portion of your calls is spam, then you’re wasting everyone’s time. 

Your employees cannot do their job. Customers cannot reach you for support or sales inquiries. Your partners cannot contact your business to complete transactions. All in all, it is an unproductive task for everyone involved. 

Improve Productivity 

The interruptions from unwanted calls cause more than lost time. Suppose your employees were in the middle of an important task or meeting. Hanging up on an unwanted caller takes just a few seconds or a minute. But the interruption may break their focus or concentration. Imagine this happens several times a day, every single day. Over the long-term, these interruptions can cost you in terms of lost productivity. The bigger your company, the bigger the loss. 

Types of Unwanted Calls 


Telemarketers belong to a group of companies that try to sell your products and services over the phone. They are different from regular companies trying to contact you. Why? In most cases, telemarketers don’t have a previous association with you. It means you have never bought anything from them or asked for information.  


Thanks to technology, telemarketers have become more efficient. Instead of using human beings to make thousands of calls, they can now use automated calling systems. These systems use recorded messages instead of actual conversation. Sometimes, they will ask you to press a number so you can be removed from that list. 


A significant portion of unwanted calls is scams. There are different types of scams based on what they are looking to get from people. For example, one common scam is to impersonate a bank or credit card company. The aim here is to make you pay for imaginary late fees or processing fee for something.  

A variation on the scam is to pretend that the user owes money to the IRS or some other government agency. A scammer will usually demand payment in the form of prepaid gift cards or money transfers that cannot be traced.  

Sometimes scammers are after information and not money. They want your account credentials such as passwords or personal/confidential information like Social Security numbers.  


This type of calls is not a significant portion of unwanted calls but they are there nevertheless. These calls tend to be personal and targeted against an employee. For instance, an angry ex-spouse may repeatedly call during working hours to interrupt their day. This kind of harassment is an emotional and mental strain on your employees. It can seriously affect their productivity and compromise their ability to do their jobs. 

Anonymous Calls 

Your first response may be to block anonymous calls. While that may work for an individual user, it is not a viable option for most businesses. What if a customer or partner calls you from a number your system doesn’t recognize? The risk of not answering legitimate calls far outweighs the lost time from unwanted calls. So just blocking anonymous calls is not a good solution. 

How to Block VoIP Calls 

Caller ID 

The first line of defense against unwanted calls is caller ID. This is a great option for employees who don’t regularly interact with customers (sales, tech support, etc.). If you get a legitimate call from a number you don’t recognize, chances are they will leave a voicemail. And you can always call them back later. 

Unfortunately, there are ways to get around this including caller ID spoofing. Scammers can show a different caller ID on your screen than the number they are calling from. Many people answer such calls because they see a local area code or a familiar number. 

Do Not Call Registry 

Another option is to register your phone number with the national Do Not Call registry. Your registration never expires and many people see a drop in unwanted calls. However, political parties, charities, and businesses that have a previous association with you can still call you. At the same time, it doesn’t stop scammers or illegal businesses either. 

File a Complaint with the FTC 

The problem of robocalling and spam calls has grown to the point that regulators are considering legal action against companies. But as you well know, these processes can take a lot of time. Until the company is shut down by law, you will still get calls from them. 

How to Block VoIP Calls at the Individual User Level 


If you happen to own a smartphone – iOS or android device – there are options in various apps to block unwanted calls. The default calling/messaging apps on both platforms can block specific numbers as well. They can also alert you to potential scams before you even answer the phone. 

Carrier services 

Most of the major carriers also filter or block unwanted calls. You can use their blacklists to make sure robocalls and spam calls don’t get through. 

How to Block VoIP Calls at the Enterprise Level 

If you have VoIP phones NoMoRoBo is a great option. It has both free and paid plans to block robocalls. The service attempts to identify robocalls by scanning a blacklist of known phone numbers. You can then decide to send the call to voicemail or answer it. It can also protect against text messages.  

Use IVR 

Using an Interactive Voice Response system is a good method to block VoIP calls. This is especially true in the case of robocalls as they cannot select options. Telemarketers and scammers will also hang up since they don’t want to waste their time.  

The Future – AI 

Technology-based on artificial intelligence will likely win the fight against spam calls in the future. Many software companies are already working on ways to identify and redirect spam calls. They can analyze calls based on origin, number patterns, and other factors. But until then, the methods we have today should suffice. 

User Awareness & Training 

Another way to reduce unwanted calls and interruptions is through user awareness and training. Make sure your employees know not to answer calls from unknown numbers. Unless you work in the sales or support departments, there is no reason to answer such calls in the first place.  

The following tips can help you manage unwanted calls: 

  • Even if the message asks you do, don’t press any number to take you off their lists. It only confirms that your number is working. 
  • Don’t waste time speaking to the caller or try to convince them to not call you later. The best option is to always hang up.  
  • Block individual numbers when you know they are spam calls. Also, use white lists or blacklists to manage calls based on known numbers. 
  • Do not click on unsolicited messages in your email or text inbox. These are often used as part of bigger scams to identify employees of the company or organization. 
  • Never give sensitive information over the phone and that includes customer or financial data, passwords and even email addresses. 
  • Make sure to report such calls to the appropriate department or team. They can always take follow-up action if necessary. 
  • Use social media responsibly and do not post work numbers online. The fewer people know your number, the safer it is. 

Knowing how to block VoIP calls can help you avoid spam and easily go about your day. Visit VoIPstudio to find out more about VoIP.  

Ready to get started with VoIPstudio?

Start a free 30 day trial now, no credit card details are needed!

Thousands of businesses across the world trust VoIPstudio for all of their most vital business communications. Why not be the next?

Thousands of businesses across the world trust VoIPstudio for all of their most vital business communications. Why not be the next?

Start a free 30 day trial now, no credit card details are needed!