Unknown Calls in Japan: How to Spot a Scam and Verify the Caller

2026年9月9日

Unknown Calls in Japan: A Practical Scam-Checking Guide

Do not trust a call simply because the screen shows a Japanese number, a police-station number, or the name of a real organization. If the caller asks for money, account details, a PIN, a verification code, or secrecy, hang up and contact the organization through a number you find independently.

This guide is for new residents, students, workers, and visitors who may not yet know how Japanese police, government offices, banks, delivery companies, and phone operators normally contact people.

Quick safety check

A number beginning with + is an international-format number, but an ordinary-looking Japanese number can also be falsified.
Police do not settle an investigation by asking you to transfer money, buy electronic money, or reveal your bank PIN.
Do not press a number during an unexpected automated call claiming that your service will be stopped.
For a non-emergency police consultation, call #9110. If a crime is happening or you are in immediate danger, call 110.
For a consumer dispute or suspicious demand for payment, call 188 to reach a local consumer affairs consultation service.

TOC

The number on your screen is only a clue

Caller ID cannot prove who is calling. It may help you decide whether to answer, but it should never be your final identity check.

A number shown as +1, +44, or another international code deserves caution when you are not expecting an overseas call. Japan’s National Police Agency has reported that many fake-police calls used international numbers beginning with +, particularly numbers beginning with +1.

However, blocking every international number is not a complete solution. The police have also confirmed calls that displayed the representative number of a real police headquarters or station. Some fraudulent international numbers were designed to end in 0110, resembling numbers used by police stations.

That means none of these details proves that a call is genuine:

a Tokyo 03 or Osaka 06 area code;
a mobile number beginning with 070, 080, or 090;
an IP-phone number beginning with 050;
a number ending in 0110;
the name of a bank, carrier, or government office on the display;
knowledge of your name, address, employer, or residence status.

Treat the caller’s request and behavior as more important than the displayed number.

Recognize the request, not just the prefix

The clearest warning signs are urgency, secrecy, and demands involving money or credentials. A suspicious caller may combine several of them.

A fake police or prosecutor call

The caller may say that your bank account, residence card, passport, or phone number was connected to a crime. You may be told that an arrest warrant exists or that you must prove your innocence.

The next step may be a request to:

move the conversation to LINE or another messaging or video-call service;
show identification during a video call;
send a photo of your passport, residence card, or bankbook;
transfer money to a “safe account” for inspection;
stay in a hotel or other private place while following instructions;
keep the investigation secret from your employer, family, bank, or local police.

A police badge, uniform, warrant image, or official-looking website shown on a video call is not proof. End the call and find the police station’s number on an official prefectural police website. Call it yourself.

An unpaid bill or service suspension call

An automated voice may claim that your phone will stop working in two hours, that an account has an unpaid balance, or that legal action will begin today. It may tell you to “press 1” to speak to an operator.

A person who answers may impersonate a mobile carrier, a government ministry, or a collection department. The National Consumer Affairs Center of Japan warns against responding to unfamiliar claims for unpaid charges, even when the caller uses the name of a real company.

Check the claim separately:

End the call without pressing any key.
Open the company’s official app, your latest bill, or its official website.
Use the contact number printed there—not a number supplied by the caller.
Ask whether your account actually has an unpaid balance or restriction.

A demand for electronic money

A request to buy gift cards or prepaid electronic money at a convenience store and reveal the code is a decisive warning sign. The National Consumer Affairs Center states that instructions to buy electronic money and disclose its number are fraudulent.

Do not follow coaching such as “Tell the cashier it is for personal use.” That instruction is designed to defeat a store employee’s fraud check.

A one-ring callback trap

Some unknown calls stop after one ring because the caller wants you to call back. NTT DOCOMO warns that returning an unfamiliar call—especially an overseas call—can lead to high international charges or connection to a malicious service.

If the call matters, a legitimate caller can usually leave voicemail, send an identifiable notice, or call again. Search for the organization independently before returning the call.

A bank, delivery, tax, or immigration story

Scammers change the organization they claim to represent, but the pressure pattern remains similar. Be cautious when an unexpected caller asks you to:

disclose a PIN, password, one-time password, or SMS verification code;
install an app or screen-sharing program;
use an ATM while staying on the call;
make a transfer to protect or test an account;
pay tax, customs fees, a fine, or a visa charge immediately;
click a link in a follow-up SMS;
hand cash, a bank card, or documents to a visiting “staff member.”

A real organization may contact you about a genuine issue. The safe response is still the same: end the incoming call and start a new contact through an official channel.

ここがポイント: A familiar logo, correct personal details, or a convincing Japanese phone number can all be copied or falsified. Verification means ending the call and contacting the organization independently.

What to do during a suspicious call

Your first job is to stop the conversation before the caller creates more pressure. You do not need to prove that it is a scam while you are still on the line.

Use this sequence:

Do not confirm personal information. Avoid giving your full name, address, date of birth, residence status, bank, employer, or family details.
Do not press keys or follow an automated menu. End the call.
Do not call back from the recent-calls screen. Look up the official number separately.
Do not open a link sent during the call. A message arriving at the same time does not make the caller genuine.
Write down what happened. Keep the displayed number, time, claimed organization, payment instructions, account information, and any related SMS.
Ask someone you trust to review it. A school office, employer, Japanese-speaking friend, hotel desk, or local support desk may help you find the correct official contact, but do not forward passwords or identity documents.

Useful Japanese phrases include:

Kakunin shite kara kakenaoshimasu — “I will check and call back.”
Kojin jōhō wa denwa de tsutaemasen — “I do not give personal information by phone.”
Kono denwa wa kirimasu — “I am ending this call.”
Keisatsu ni sōdan shimasu — “I will consult the police.”

You do not need to remain polite under pressure. Hang up.

How to verify a caller safely

A safe verification uses contact information that the caller did not control. This breaks the connection between the suspicious call and your next action.

Police or a government office

Search for the official website of the relevant prefectural police, city, ward, ministry, or agency. Check that the web address belongs to an official government domain, and call the published main number.

If the caller claims to be from a police station, give the official operator the caller’s stated name, division, and case details. Do not rely on the incoming number, even if it matches the number listed online.

A bank or card company

Use the number printed on the back of your card, inside the bank’s official app, or on a statement you already possessed. Do not use a number or link from the suspicious caller.

Bank staff may ask security questions after you call an official number. That is different from an unexpected caller demanding your PIN or one-time password.

A phone, utility, or delivery company

Check the official app, customer portal, contract papers, bill, or missed-delivery notice. Search results and online advertisements can sometimes lead to imitation sites, so an app or document you already trust is preferable.

Your employer or school

If a caller claims that your workplace or school referred a payment, immigration, or disciplinary matter, contact the responsible office directly. Use an internal directory, student portal, or a number already known to you.

Protect your phone before the next call

The best setting is one that reduces contact without blocking calls you genuinely need. The exact tools depend on your device, carrier, contract, and whether you use a mobile or landline.

On a smartphone

Consider the following:

turn on spam or caller-warning features provided by your phone or carrier;
silence unknown callers if you can safely review voicemail later;
block individual numbers after suspicious calls;
disable link previews or avoid opening links from unknown SMS senders;
keep the operating system and security updates current;
protect carrier and messaging accounts with strong, unique passwords;
never share an SMS verification code with an incoming caller.

Be careful with aggressive blocking if you are waiting for calls from a hospital, delivery driver, school, employer, immigration professional, or municipal office. Some legitimate calls may come from an unfamiliar switchboard or withheld number. Voicemail screening can be a better compromise.

On a landline

A recording or answering-machine function can prevent direct conversation with an unknown caller. The National Police Agency recommends measures that reduce the chance of speaking with a fraudster, including caller display, rejection of withheld numbers, warning messages, and call recording.

People who do not need international calls on a landline may also investigate an international-call suspension service. Availability and conditions depend on the line and operator, so confirm the effect before applying—especially if family, work, or medical contacts may call from overseas.

Know the limitation of blocking

Blocking one number stops only that number on that device or service. Scammers can change numbers, use internet calling, or falsify caller ID. A spam warning is useful, but no label can guarantee that an unmarked call is safe.

If you already answered or shared information

Answering alone does not mean you have lost money, but act quickly if you disclosed credentials, installed software, or made a payment. Preserve evidence before deleting messages or call records.

If you only spoke to the caller

Block the number if appropriate.
Save the time, number, and summary of the conversation.
Expect possible follow-up calls using a different identity or number.
Tell household members if the caller learned family details.

If you shared a password or verification code

Contact the affected bank, card issuer, carrier, or online service through its official channel.
Change the password from a trusted device.
End unknown login sessions where the service provides that option.
Review recent transactions, account recovery details, forwarding settings, and registered devices.

Disconnect the device from the network if you believe someone still has remote access. Contact the relevant financial institutions from another trusted device, and seek technical help before using the affected phone or computer for banking.

Do not continue following instructions from a person who claims that another payment will recover the first one.

If you transferred money or supplied a card number

Call your bank or card issuer immediately through an official number and explain that the transaction may be fraudulent. Whether a transfer can be stopped or funds recovered depends on timing and the payment method, so speed matters.

Then contact the police. Use 110 if the crime is in progress, someone is coming to collect money or a card, or you face immediate danger. For a non-emergency consultation, use #9110 or contact your nearest police station.

Which consultation number should you use?

Choose the service according to the situation; these numbers are not interchangeable. Language support and operating hours can differ by prefecture or service.

110 — emergency police: Use when a crime is happening, a collector is on the way, or you are in immediate danger.
#9110 — keisatsu sōdan sen’yō denwa (police consultation line): Use for non-emergency concerns about a suspicious call or possible crime. It connects callers to the police consultation desk for the area from which the call is made. If #9110 does not connect from your phone, find the consultation number for your prefectural police.
188 — shōhisha hottorain (Consumer Hotline): Use for suspicious bills, contracts, sales calls, or other consumer problems. It routes callers to a nearby consumer affairs consultation office. Availability and language support vary locally.
Consumer Hotline for Tourists: Foreign visitors can use the National Consumer Affairs Center’s multilingual telephone consultation service for consumer problems during a trip. It is a paid call and provides advice rather than police or legal enforcement.

If Japanese is difficult, say “Eigo onegaishimasu” (“English, please”) and state your location slowly. Interpretation arrangements vary, so a trusted person or local international association may also help with a non-emergency consultation.

Common mistakes that make verification weaker

Most mistakes happen because the caller controls the pace or the contact route. Slow the process down and rebuild it from a source you trust.

Avoid these traps:

Searching only the number: A matching online listing does not defeat caller-ID spoofing.
Calling back immediately: You may reach the fraudster again or incur an international charge.
Using a number provided by the caller: A fake department can give you another member of the same group.
Assuming young people are not targeted: National Police Agency data for the first half of 2025 showed fake-police victims across age groups, with people in their 20s and 30s forming the largest groups in that dataset.
Continuing the call to gather evidence: More conversation gives the caller more chances to obtain information or increase pressure.
Believing secrecy proves seriousness: Instructions not to contact family, an employer, a bank, or local police are a major warning sign.
Treating Japanese fluency as proof: A genuine-sounding script, police vocabulary, or knowledge of local procedures does not verify identity.

Current warning: fake-police calls can look official

As of August 2026, fake-police impersonation remains a central official warning in Japan. The important change is not merely the use of overseas numbers; it is the use of stronger visual and technical imitation.

Reported methods include:

spoofing a real police headquarters or station number;
using international numbers designed to resemble police numbers;
moving targets to video calls;
showing false police identification or arrest-warrant images;
directing targets to fake police websites;
claiming that a bank account or phone number was used in a crime.

The practical consequence is simple: recognizing prefixes is no longer enough. The reliable defense is an independent callback to an official number, combined with a refusal to transfer money or disclose credentials during an incoming call.

A 30-second response plan

Keep this short routine near your phone:

Hang up.
Save the number, time, voicemail, and messages.
Do not press keys, click links, or call back.
Find the organization’s official contact yourself.
Call your bank immediately if money or credentials were involved.
Use #9110 for non-emergency police advice, 110 for immediate danger, or 188 for a consumer problem.

A suspicious prefix can warn you. It cannot clear a caller. The next watchpoint is always the same: who chose the number used for verification—you, or the person asking for money?

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