Incoming calls with "no notification" are too dangerous! Learn how to block incoming calls!

By momoka

Have you ever received a "Not Notifiable" call on your cell phone? What is "Not Notifiable"? I want to reject a call from a phone I have no idea about! This article will show you how to reject incoming calls from "Notifiable" numbers.

What is "Notifiable"?

An incoming call with a "Do Not Notify" number is an indication that a phone number cannot be notified due to restrictions imposed by telecommunication companies, lines, or other factors.

  • International Calls
  • Shinkansen
  • Skype, etc.

This is displayed when an incoming call is received from a phone whose phone number cannot be displayed on the system.

International Calls

Incoming calls from international phones may be displayed as "Notification not available".


Incoming calls from Shinkansen and public phones may also be displayed as "Not Notify Me".


Skype has a dedicated number to notify the other party of outgoing calls. However, this feature is not supported in Japan, so when you call Skype from Japan, the other party will see the message "Notification not possible.

Since these IP lines can be obtained in large numbers for free, they are often used by dating sites to call their customers.

Since IP lines can be obtained in large numbers for free and can be used to communicate with caller-notifiable, be aware that they may be used for crimes involving the police, such as bank transfer scams.

The Dangers of "Do Not Call" Calls

Un-notifiable" calls are too dangerous, and if you don't reject them, you could be victimized!

Possible Leakage of Personal Information

If you are receiving many blocked calls, there is a possibility that your personal information has been leaked. There are opportunities to hand over personal information in casual everyday situations, such as entering a sweepstakes or applying for a gift, but there are also malicious companies that leak or sell this information to outside parties.

We also often hear of incidents where company databases are hacked or information is stolen by exploiting security vulnerabilities. If you receive many unanswered calls, consider the possibility that your personal information has been compromised.

Possibility of being used for fraud

Some blocked calls may be used as a means of phone fraud, such as bank transfer scams. The person on the other end of the blocked call may be trying to set up a bank transfer scam. It is unlikely that someone trying to scam you in the first place would notify you of their phone number, so there may be some underlying reason.

Possibility of sales calls

Calls for sales purposes, such as sales calls and solicitation calls, are often blocked from the outset. Generally speaking, blocked numbers are not good for sales efficiency because callers often distrust such calls. However, if a phone number is notified, it is possible to register the number in the phone book and set "reject calls from this number. Companies specializing in sales calls often call the same phone number repeatedly for various purposes. To avoid this problem, some companies use blocked numbers.

Possible criminal intent.

In some cases, blocked calls are used as a means of checking to see if someone is home before a burglar or robber enters the house. Since not answering the phone means that you are not at home, it is dangerous not to answer the phone just because it is a blocked number. You should consider some countermeasures, especially if you have a landline at home.

How to reject "No Notification

The following is an explanation of how to reject "No Notification".

Do not answer calls from "Do Not Notify

The easiest way to immediately reject an incoming "Do Not Not Notify" call is to not answer the incoming call.

If the call is an international call and it is an "international roaming" call, the person who answers the call may be charged a higher rate. Therefore, if you answer an incoming call, we recommend that you hang up immediately.

Even if someone you know is calling from overseas or on a bullet train because they want to talk to you, if you do not answer the incoming call, they will think of something else to do.

Use an anti-spam service.

Each of the major telecommunications carriers has its own "anti-spam" service. The following names and fees are available from the three major carriers.

  • docomo "Nuisance Call Stop Service" (free of charge)
  • Softbank "Number Block" (charged/100 yen/month excluding tax)
  • au "Nuisance Call Dismissal Service" (charged/100 yen/month excluding tax)

These services allow you to reject unwanted calls. Detailed instructions on how to use these services will be described later in detail.

Using the iPhone's Good Night Mode

If you want to reject calls with "no notifications" on your iPhone, "Good night mode" is useful.

First, open the "Settings" application on your iPhone and tap "Intensive Mode.

When "Intensive Mode" opens, tap "Good Night Mode.

Once "Good Night Mode" is open, tap "Contacts".

When "Contacts" opens, tap "Incoming Calls".

When "Incoming calls" opens, tap "All contacts".

You can now reject "No Notification" calls. In addition to "No Notification", "Blocked Calls" and "Public Calls" will also be blocked.

How to reject incoming calls from "Notifications not available" on Android

Android has a convenient setting that allows you to reject incoming calls from "no-notification" calls.

1. Select the "Phone (Dial)" application.

2. Select "Menu button (icon with vertical ...)

Select "Communication Settings

4. Select "Call Rejection Settings

Turn on "Reject incoming calls

Turn on "No Notification