A spam call blocker app is a phone or computer application that allows you to block unwanted calls from unknown callers or from numbers you have manually blacklisted.

If you don't recognise the number behind an incoming call and you are keen to avoid any spam or robocalls, most call blocker apps allow you to search for that number on their database to find out if anyone else has received unwanted calls from them or if the number is in fact harmless.

So what are some of the best call blocker apps currently available? What different features do they all have? And how do you know which you should choose to suit your needs best?

We are going to help you find answers to these questions as we run through the top 10 spam call blocker apps.

Our top 10 spam call blocker apps are:

  • Robo Shield
  • CallApp
  • Truecaller
  • Unknown Phone
  • Calls Blacklist
  • Nomorobo Robocall Blocking
  • Call Control
  • YouMail Voicemail & Spam Blocker
  • RoboKiller
  • Hiya

So let's jump in and take a closer look at each of these apps.

Robo Shield

Robo Shield is a call-blocking software that is built to serve businesses. It blocks spam calls from a database of numbers from around the world that are known to be linked to spammers. The database is constantly growing to ensure any new spam numbers are quickly added to its list.

With Robo Shield, you can also manually block numbers you know to be spam or unwanted by adding them to your own blocklist. However, Roboshield does not block spam texts, such as smishing messages.

There is both a free and pro version of Robo Shield. The free version will inform you that a caller is using a number on their blocklist, but it won't actually block the call.


CallApp has called ID, call blocking, and call recording features. It provides information about the incoming caller or the call recipient by connecting to the app users' community-generated networking services.

CallApp can tell you if a caller is from a marketing company, a spam number, or a robocall number. You can block and blacklist unwanted calls.

The basic app is free, though paid upgrade versions are also available.


Truecaller is a spam call-blocking app designed by a Swedish company. It is now one of the most downloaded call-blocking apps in the world, with over 330 million users worldwide.

Truecaller offers call blocking, caller ID, flash messaging, and recording features. It can also organise your SMS inbox into Personal, Important, Other, and Spam categories to ensure your phone is kept well-ordered and secure.

There are free and premium versions available.


UnkownPhone is a website and an app that performs reverse phone number searches to see if the number has a history of being reported as spam. If you get a missed call from a number that is not saved to your phone, type the number into UknownPhone, and it will search its ever-growing database to see what information they have on it.

UnknownPhone does not offer call-blocking services. Instead, it allows you to perform an entirely free search of any number you want.

Calls Blacklist

Calls Blacklist blocks both spam calls and spam SMS. It can block calls and text messages from private or unknown numbers and specific numbers you do not want to hear from. You can also save your own blacklist of numbers and import them from one device to another.

There are both free and premium subscriptions available.


Nomorobo offers 100% protection from all robocalls. It is ideal for anyone who wants to completely block all numbers that have been deemed to be connected to spam callers. It also offers protection against scam SMS messages.

Nomorobo is free for VoIP landlines. There are also premium versions available for mobiles and access to advanced features.

Call Control

Call Control allows you to block calls on your home, business, or mobile phone. You can block calls from numbers linked to scammers and robocalls and create your own personal blocklist. Call Control also offers a free number reverse directory so that you can find out who is behind an unknown number.

Call Control has both free and premium versions available.


YouMail is great for businesses and consumers in the UK and the US. It blocks known robocalls and spammers and can identify voicemail spam too. YouMail will not only block unwanted spam calls, but it will also help to get you off spam lists as well.

There are free and premium versions available for personal use. Business models are all costed.


RoboKiller identifies spam calls as the call your phone and then sends the spammers to a fake voicemail to waste their time and record their voices and antics. The more time wasted by the scammers, the less time they have to scam other people, so RoboKiller protects you and others.

You can even choose your own voicemail bot voice.

RoboKiller has a global database of scam numbers and can even recognise when scammers are spoofing. You can customise the level of call blocking you want to implement in case you feel too many calls are being blocked.

There are both free and premium versions available for businesses and individual consumers.


Hiya is another highly popular call-blocking app. A number of well-known businesses use Hiya for their own operations, and it is well-trusted and respected within the industry.

Hiya allows you to block specific numbers you want to avoid and auto-block spam numbers from their database. It also has a reverse number lookup option. You can also share your contacts with them (if you want to) so you know that no wanted calls will be blocked.

Hiya has both free and premium versions.

A spam call will not only waste your time, but it also comes with a number of risks that could potentially be harmful to you or your business. A spam caller may ask you to share sensitive information with them or demand that you make a payment for a fraudulent debt collection. If you miss a call from a spam caller, you may even be charged a premium rate to return their call.

Spam messages can be equally harmful and may even be more difficult to detect than spam calls. A spam message may contain a harmful link that you click absent-mindedly whilst not paying attention. And again, replying to a spam message could end up charging your phone and sending the money to the spammer.

If you receive a spam call and either you don't have a spam call blocker or your app didn't block it, make sure you upload the number to a database so that other people are protected against this number in the future. You should leave as much information regarding the call as possible. For example, make a note of how long they rang for, how many times they called, what the content of their call or message was, what time of day they rang, etc.

If you receive a call that you are suspicious of, feel free to inform the caller that you are going to hang up and call them back. Many spam callers pose as official bodies, such as your bank or HMRC, and you have every right to clarify the call is genuine by ending the conversation and redialling them of your own accord.

If you receive a call from an unknown number, you might want to consider not answering it and checking the number in a spam number database before calling it back.

Phone numbers that start with 09 are usually very expensive to dial, so beware of calling them back before you have clarified exactly who is on the other line. You should also be cautious of redialling any 070 numbers as they cost a lot too.

To be safe, always search for any numbers starting with the following dial codes:

  • 09
  • 070
  • 0871
  • 0872
  • 0873
  • 118
  • Any number that starts with a 5, 6, 7, or 8
  • All numbers that look too short

You can always search for the number later; if it is genuine, you can redial.

If you can't find the number that has called you, it is important to remember that any legitimate organisation should have more than one point of contact for you. For example, your bank, HMRC, or phone provider should also have your home and email address. If they need to contact you urgently, they will reach out through a number of avenues.

Spam call blocker apps allow you to block scam calls from numbers that are known to be malicious. You can also create your own blacklist and block all unknown calls. Most of the apps also enable you to search the number from any incoming calls you have received or missed, so you can check its authenticity before picking up or calling them back.

You can download most of the apps in our list from Google Play or the Apple App Store. Install one today to ensure you will never waste time talking to a robocall or scam caller again.