Data-Only SIM | A Cost-Effective Way to Use the Internet Comfortably - GTN MAGAZINE
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（更新日：2026年03月08日）

Data-Only SIM | A Cost-Effective Way to Use the Internet Comfortably

Internet connectivity is one of the most important preparations for foreigners planning to travel or stay in Japan.

Smartphones have become essential tools for modern travel—whether you're searching for tourist spots, getting directions through map apps, using translation apps, or sharing memories on social media.

In this article, we'll provide a detailed explanation of "data-only SIMs" for foreigners visiting Japan or those already staying here.

We'll thoroughly introduce methods to use the internet both cost-effectively and comfortably.

What is a Data-Only SIM?

A data-only SIM is a SIM card that specializes in internet connectivity without voice call functionality.

No phone number is assigned, and traditional phone calls (making and receiving calls using numbers like 090 or 080) are not possible. However, you can use data communication to browse the internet, use apps, and exchange emails.

Features of Data-Only SIMs

  1. Low Cost: Basic fees are cheaper than SIMs with voice call functionality
  2. Simple Procedures: In many cases, no ID verification required (especially for short-term prepaid types)
  3. Immediate Use: Available for immediate use after purchase at convenience stores or airports
  4. Time-Limited Plans: Choose from 1 day to 180 days based on your visit duration
  5. Data Capacity Options: Various capacity options available according to your usage needs

Types of Data-Only SIMs

There are mainly three types of data-only SIMs:

Physical SIM Cards (Traditional Type)

These require inserting an actual card into your device. There are three sizes: "Standard SIM," "microSIM," and "nanoSIM," but recent smartphones mainly use "nanoSIM."

Many prepaid data SIMs are "multi-cut SIMs" that can accommodate any size.

eSIM (Embedded SIM)

An electronic SIM without a physical card that is set up on your device by scanning a QR code.

Available on latest models such as iPhone XS and later, Google Pixel 3 and later, and Samsung Galaxy S20 and later.

No card replacement is required, and you can activate service instantly online.

Prepaid vs. Postpaid Types

Prepaid Type: Pay in advance and use for a predetermined period and data amount.

This type is mainly offered for foreign visitors to Japan.

Postpaid Type: Pay for usage afterward. Usually requires a contract and is intended for long-term residents in Japan.

Recommended Data-Only SIM Plans for Foreign Visitors

The recommended data-only SIM is GTN Prepaid Data SIM.

It features easy application with just a passport and large data capacity plans.

GTN Prepaid Data SIM

GTN Prepaid Data SIM is a data-only prepaid SIM available from a minimum of 7 days to a maximum of 90 days.

You can apply with just a passport, and it features 5G/LTE network coverage and customer support in 8 languages. It's a service for short to medium-term visitors with limitations such as speed reduction after data exhaustion and no extension options.

Operating CompanyGlobal Trust Networks Co., Ltd.
PricingData-Only SIM/eSIM

 
Official Websitehttps://www.gtn-mobile.com/

Where to Purchase Data-Only SIMs

Main locations where foreign visitors can purchase data-only SIMs:

Airports

Advantages: Available immediately upon arrival in Japan, ready to use right away

Disadvantages: Slightly higher prices

Main Locations:

  • Narita International Airport
  • Haneda Airport
  • Kansai International Airport
  • Chubu Centrair International Airport
  • New Chitose Airport
  • Fukuoka Airport

Available at various counters and shops within airports. Also available at airline-affiliated counters like JALABC.

Convenience Stores

Advantages: Located nationwide, easy to purchase during your stay

Disadvantages: Inventory and product availability may vary

Main Retailers:

  • Lawson (Japan Travel SIM, etc.)
  • NewDays (Japan Travel SIM, etc.)
  • 7-Eleven (selected products)
  • FamilyMart (selected products)

Electronics Retailers

Advantages: Wide variety, staff explanations available

Disadvantages: Limited number of stores

Main Retailers:

  • Bic Camera
  • Yodobashi Camera
  • Yamada Denki

Online Shops

Advantages: Pre-order available, most options, eSIM available for immediate use

Disadvantages: Physical SIM requires delivery

Main Purchase Options:

  • Amazon.co.jp
  • Official SIM provider websites
  • Travel booking sites (Klook, etc.)

Key Points for Choosing Data-Only SIMs

Points to consider when foreign visitors choose data-only SIMs:

Selection Based on Stay Duration

Stay DurationRecommended Plans
Short trips within 1 week7-day/10-day plans (around 3GB-10GB)
Trips around 2 weeks15-day/21-day plans (around 10GB-20GB)
Stays around 1 month30-day plans (20GB+)
Long-term stays (3+ months)90-day to 180-day plans (50GB-100GB)

Data Capacity Guidelines

Main UsageRecommended Data Capacity (per week)
Mainly email, maps, text messages1-2GB
Frequent SNS posts and photo uploads3-5GB
Video streaming and video calls7-10GB
Heavy video streaming, online gaming15GB+

Device Compatibility Check

To use a data-only SIM, the following conditions must be met:

  • SIM unlocked (or originally SIM-free device)
  • Compatible with frequency bands used in Japan
  • APN settings configurable
  • eSIM-compatible device for eSIM

Especially for devices brought from overseas, we recommend checking compatibility with Japanese communication bands in advance.

Choosing Between eSIM and SIM Cards

TypeAdvantagesDisadvantages
eSIM• No card replacement needed
• Instant online activation
• Multiple eSIM switching possible		• Limited compatible devices
• Somewhat complex setup
Physical SIM• Compatible with almost all SIM-free devices
• Relatively easy setup		• Card insertion required
• Risk of loss

How to Set Up Data-Only SIMs

Setup methods for starting to use data-only SIMs:

For Physical SIM Cards

Installing the SIM Card

  • Turn off your device
  • Remove the SIM card tray (using a dedicated pin or paper clip)
  • Place the correct size SIM card in the tray
  • Replace the tray
  • Turn on your device

APN Settings

  • Open your device's "Settings" menu
  • Select "Mobile Network" or "Cellular Data"
  • Select "Access Point Names" or "APN"
  • Add "New APN"
  • Enter the configuration information listed on the SIM package
  • Save settings

Enable Data Roaming

  • Turn on "Data Roaming" from "Settings" > "Mobile Network"

For eSIM

Scan QR Code

  • Scan the eSIM QR code with your camera app
  • Or manually enter the provided code

Download eSIM Profile

  • Follow on-screen instructions to download and install the eSIM profile

Activate eSIM

  • Select the eSIM line from "Settings" > "Cellular"
  • Turn it "On"

Common Setup Issues and Solutions

IssueSolution
Cannot connect to internet• Check if data communication is on
• Verify APN settings are correct
• Try turning airplane mode on/off
Slow communication speed• Check available data capacity
• Try a different location
• Restart your device
Cannot download eSIM• Check Wi-Fi connection
• Verify device supports eSIM
• Check if QR code is read correctly

Common Questions from Foreign Visitors

Q1: Can I make phone calls with a data-only SIM?

A: Traditional phone line calls are not possible, but internet calls (VoIP) using apps like LINE, WhatsApp, and Skype are available.

Q2: Can I use SMS verification?

A: Standard data-only SIMs don't have SMS functionality, so it's not available. If you plan to use services requiring SMS verification, consider choosing a data SIM with SMS functionality.

Q3: Can I use it anywhere in Japan?

A: Generally, it works fine in major cities and tourist areas. However, communication may be limited in mountainous areas or remote islands. SIMs using NTT Docomo networks offer the widest coverage area.

Q4: What happens when I use up my data capacity?

A: Most prepaid SIMs significantly limit communication speed (around 128kbps) when data capacity is exhausted. Some services allow additional top-ups.

Q5: Is tethering (internet sharing) possible?

A: Many data-only SIMs support tethering, but some services may have restrictions. If you specifically want to use tethering, check compatibility in advance.

Precautions When Using Data-Only SIMs

Managing Data Usage

Prepaid data-only SIMs only allow predetermined data capacity usage. To avoid running out of data during your stay in Japan, pay attention to the following:

  • High-resolution video streaming consumes large amounts of data
  • Turn off automatic app updates
  • Use Wi-Fi when available at hotels, etc.
  • Regularly check data usage

Checking Coverage Areas

It's reassuring to check in advance whether the places you plan to visit are within coverage areas. This is especially important when visiting rural or mountainous areas. You can check coverage maps on SIM provider websites.

Multi-Device Usage Restrictions

Some SIM cards may have restrictions on use with multiple devices. For example, some services prohibit switching SIMs from smartphones to tablets. Check the terms of service.

Security Measures

While safer than public Wi-Fi, basic security measures are still necessary when using data-only SIMs:

  • Keep OS and apps updated
  • Avoid accessing suspicious sites
  • Consider using a VPN

Alternatives to Data-Only SIMs

There are other ways to access the internet during your stay in Japan besides data-only SIMs. Let's compare the advantages and disadvantages of each:

Pocket Wi-Fi (Mobile Router) Rental

Advantages

  • Can be used simultaneously with multiple devices
  • Stable signal
  • Many plans with large capacity

Disadvantages

  • Need to carry additional equipment
  • Battery life concerns
  • Often slightly more expensive than SIMs

Hotel and Cafe Wi-Fi

Advantages

  • Often free
  • No need to worry about data usage

Disadvantages

  • Connection may be unstable
  • Security risks
  • Cannot use when out and about

International Roaming

Advantages

  • Can use your home country phone number as is
  • No SIM replacement hassle

Disadvantages

  • Can be extremely expensive
  • Often strict data limitations
  • Some functions may be restricted

Conclusion

For foreign visitors to Japan, data-only SIMs are a cost-effective internet connection solution.

By choosing the optimal plan based on your stay duration and usage purpose, you can support a comfortable stay in Japan.

The proliferation of eSIMs has made advance preparation even easier. You can purchase online before arriving in Japan and start using the internet immediately upon arrival at the airport.

Find the communication solution that suits you from various options, and enjoy your stay in Japan to the fullest without worrying about connectivity. By preparing systematically, your wonderful Japanese experience will become even more fulfilling.

 

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