Call blocking refers to intercepting and stopping unwanted calls before they reach their intended destinations. This is used to stop unwanted calls, including illegal robocalls and calls from suspected scammers. Call blocking may be achieved with a device built for that purpose or technologies meant to screen incoming calls.
Call blocking can help avoid phone scammers and stalkers. It can significantly reduce the number of unsolicited calls received, especially sales calls from telemarketers. It is possible to block incoming calls on traditional landline phones as well as mobile and VoIP phones. For each of these, there are multiple methods for blocking unwanted calls. However, strict call blocking rules may block some legitimate calls.
What is Call Labeling?
Call labeling is the term used for flagging suspected spam and scam calls rather than outrightly blocking them. If you do decide to block calls from everyone not on your contact list, you may miss important calls from strangers trying to reach you. With call labeling, certain tags show up on your phone whenever it receives calls from known or suspected phone numbers used for scams and spam calls. You can then decide whether or not to answer such calls.
Call labeling is not as strict as call blocking, but it can be time-saving for those expecting calls from strangers as well as those whose jobs require receiving lots of cold calls. On the other hand, call labeling does not stop your phone from ringing as call blocking does. Therefore, it does not remove the annoyance of having your phone ring repeatedly throughout the day with calls from false leads and scammers.
How to Block Calls on a Mobile Phone
The three ways to block unwanted calls on a mobile phone are:
- Carrier call blocking services
- Built-in call blocking features on phones
- Call blocking mobile apps
Carrier Call Blocking Services
All the major cell service carriers offer call blocking features. These may be add-on services or included in their regular plans. Contact your carrier to ask for the options available. AT&T bundles this feature with its AT&T Call Protect service for iPhone and Android phone users. It allows subscribers to build personalized call block lists and sends unknown callers to voicemail. This bundle also includes caller ID and reverse phone number lookup, two features useful for identifying unknown callers.
Built-In Call Blocking Features on Phones
iPhones and Android phones also have built-in call blocking features. These are easy to find in the settings menus and phone apps of these devices. With such features, phone users can block phone numbers responsible for repeated unsolicited calls. There are also options to block individual numbers or all callers not in users’ contact lists.
Call Blocking Mobile Apps
The app stores for iPhones and Android phones also host lots of third-party call blocking apps. These mobile apps offer varying numbers of feature sets. Some of them are free, ad-supported apps, while others are paid apps. A few require monthly or annual subscriptions. These apps act like filters and offer users different options for handling unwanted calls. Call blocking apps can let unwanted calls:
- Ring silently
- Go to voicemail
- Fail to ring at all
Generally, call blocking apps rely on their users to identify phone numbers used for spam calls, scam calls, and robocalls. This crowdsourced approach helps them build databases that stay current and relevant. On the other hand, a call blocking app requires a lot of active users to be effective at identifying unsolicited calls.
How to Block Calls on a VoIP Phone
VoIP phone users have two options for blocking unwanted calls. They can:
- Ask their carriers for such services
- Sign up for internet-based call blocking services from third-party providers
Some VoIP service providers offer call blocking options for their users. Call your provider’s customer care line to ask if such service is available and whether it is free or costs extra fees. VoIP phone services that do not offer call blocking usually partner with or recommend third-party call blocking services.
Generally, internet-based call blocking tools allow users to set unwanted calls to:
- Ring silently
- Never ring
- Go to a spam folder
- Go to voicemail
How to Block Calls on a Landline Phone
Landline use has declined since mobile phone adoption and VoIP use increased. According to data from the National Health Interview Survey, about 3.9 percent of Americans over 18 still use landlines as of 2019. This number is expected to decline drastically in the coming decade.
Some landline phone carriers also offer call blocking services. These are usually the ones with mobile phone networks, VoIP operators, and ISPs (internet service providers). As for VoIP and mobile phones, these call blocking services may be free as part of users' phone plans or offered as paid add-ons. Call your landline phone service provider to know the options available.
The second call blocking option for landline phone users is a call blocking device. Call blocking devices offer hardware-based solutions to stopping unwanted calls. These are small boxes that connect to landline phones and filter incoming calls. Many call blocking boxes let users create blacklists of phone numbers they wish to block. Others have built-in blacklist databases and allow users to update these with numbers they want to block.
A landline call blocking box runs incoming calls through its blacklist. When it finds a match, it may:
- Block the call
- Direct the call to voicemail
- Play a recording that can fool robocalls but let actual callers through
- Allow the call but only indicate it with a blinking light rather than an audible ring
Call blocking boxes may also filter incoming calls with whitelists. A whitelist contains phone numbers allowed to ring the landline phone. This lets the user limit incoming callers to only known individuals or select callers. A whitelist is also an easy way to set up a DND (do not disturb) rule for a landline phone.
Does the National Do Not Call Registry Block Unwanted Calls?
The Do Not Call Registry does not block calls, and neither does the Federal Trade Commission (FTC), the agency responsible for creating and maintaining it. This Registry is a database of phone numbers that wish not to be contacted by unsolicited calls. Such calls are mostly from telemarketers. However, only organizations that obey the law abide by the rules of the National Do Not Call Registry. Fraudulent telemarketers and scammers do not care about the Registry and definitely call numbers listed in its database.
Although putting your phone number on the National Do Not Call Registry does not stop some unwanted calls, it can reduce the number of unsolicited calls received. In addition, you can safely assume unwanted calls received after putting your phone number on the National Do Not Call Registry are from scammers and dubious telemarketers.
Note that some unsolicited calls from certain legitimate organizations are allowed by the FTC. Legitimate unsolicited calls you may receive after adding your phone number to the National Do Not Call Registry include those from:
- Political campaigns
- Charities and non-profit organizations
- Survey groups
- Bill and debt collection agencies
Just like the National Do Not Call Registry, the 12 states Do Not Call Lists currently active in the US cannot block unwanted calls. The only ways to block unwanted calls are at the carrier level, on your phone, and with call blocking mobile apps.
Does Call Blocking Stop Robocalls?
Robocalls are unsolicited calls placed by autodialers to deliver pre-recorded messages. These were mostly used by political campaigns and telemarketers. However, the ease and speed of deploying them, as well as the minimal human intervention required, made robocalls appealing to phone scammers. Currently, most robocalls are from scammers fishing for targets and trying to defraud unsuspecting phone users or steal confidential information.
Call blocking solutions can stop robocalls. Phone users that set their devices to only ring for calls from those on their contact lists will enjoy sharp declines in the numbers of robocalls received. Users relying on carriers and mobile apps, as well as those that set lenient blocking rules on their phones, may still receive some robocalls.
Call blocking services usually rely on user-submitted information for identifying phone numbers used for robocalls. Therefore, it may take a few days for a new number used for robocalls to be flagged. If you receive a robocall after enabling call blocking on your phone, hang up immediately. You may tag the number used to add it to the blacklist on your phone or the databases of blocked numbers maintained by your carrier or call blocking app.
What Are Restricted Calls?
Restricted calls are from numbers hidden from call recipients. When you receive a restricted call, your phone’s caller ID shows “Restricted” on the phone screen. This means that the caller does not wish to be identified, at least until you answer the call.
There are different ways to make your call appear to be coming from a restricted number. You may change the caller ID setting on your phone to hide your number from everyone or just the people not on your contact list. It is also possible to quickly and temporarily make your number restricted for one call. Simply type *67 in front of the phone number you are dialing.
The Need for Restricted Calls
The two major reasons for making your number appear restricted on calls are privacy and security. If you prefer to keep your number hidden from the person you are calling, it may be because you do not wish to talk to them again or because you are afraid they will keep calling or calling at inopportune times. For example, a physician may prefer that patients do not have his home number.
Individuals likely to be stalked or harassed over the phone may also keep their numbers restricted for security reasons. Keeping your number private in this way is one way to avoid it getting shared in public.
Should You Block Calls from Restricted Numbers?
Scammers and stalkers also use restricted numbers to hide their identities while they harass and con their targets. While a restricted call may be from a legitimate caller, you may wish to not take the chance and simply not answer the call.
To stop receiving this call, you can set your phone not to ring out calls from blocked numbers. Another way to block calls from restricted numbers is by signing up for such a feature from your carrier. Some phone carriers offer plans that let subscribers block calls from anonymous callers.
Letting restricted calls go to voicemail is a cautious way to deal with these calls. However, if they end up being important calls, it can be difficult to retrieve the caller’s number to return the call. One possible way to get the number of a caller using a restricted number is to check your phone bill when you receive it. Make sure to note the call’s time and date. You may then call this number back or use a reverse phone lookup search to identify the caller.