If you are preparing for study abroad, a working holiday, or a long-term business trip to Japan, one of your biggest concerns is likely 'keeping your Korean phone number' and managing your 'Korean number while studying in Japan.' Since most Korean services—such as financial transactions, portal logins, and government tasks—rely on 'mobile identity verification,' you will frequently need to keep your Korean number active while living abroad.
However, paying your Korean carrier's regular plan while also paying for local Japanese data can be a heavy financial double-burden. In this article, we will share a practical guide to cleanly solving the Korean number retention and Japanese data dilemma, allowing you to pass overseas identity verification smoothly while smartly saving on communication costs.
Why You Need to Keep Your Korean Number and Get Cheap Japanese Data
In the past, many people temporarily suspended or canceled their Korean numbers when leaving for a long-term stay abroad. However, keeping your Korean number active has recently become essential for the following reasons:
- Identity Verification Services: Almost all online services, such as logging into Korean banking apps, making card payments, and finding passwords, require SMS identity verification through a Korean number.
- Public and Tax Services: Simple authentication or SMS verification is required when using public services like Government24 or Hometax.
- Maintaining Existing Accounts: You can quickly respond to KakaoTalk re-verification or security enhancement measures for existing Korean service accounts.
Therefore, rather than just keeping the number alive, the key is to 'maintain a state where you can receive Korean SMS in Japan.'
2 Ways to Keep Your Korean Phone Number Active on a Budget
There are two main ways to keep your Korean number active while minimizing your monthly fixed expenses.
1. Temporary Suspension with Major Carriers (Not Recommended)
This method involves using the long-term temporary suspension system of major carriers (SKT, KT, LGU+). Your number is maintained for a monthly suspension fee of about 3,000 to 4,000 KRW.
- Disadvantage: You cannot receive SMS while suspended. This means you cannot receive verification texts abroad, making it highly inconvenient as you would have to temporarily lift the suspension every time you need verification.
2. Switching to a Budget Carrier (MVNO) Ultra-Low-Cost Plan (Highly Recommended)
This is currently the most popular method among long-term overseas residents. You transfer your number to a budget carrier plan with a very low basic fee (around 1,000 to 3,000 KRW per month, or even 0 KRW during promotions) before leaving the country.
- Advantage: Since the line is 'active' rather than suspended, you can receive identity verification SMS for free via roaming in Japan. (However, making calls or using data will incur charges, so you must turn off cellular data in your smartphone settings.)
Finding the Right Data Solution in Japan
Once you have set up your Korean number cheaply with a budget carrier, you need to prepare the data you will use in Japan. It is important to choose the most reasonable option based on your length of stay and purpose.
1. Short-term Trips & Initial Arrival: eSIM and Pocket Wi-Fi
- eSIM: You can use the 'Dual SIM' feature to activate a Korean SIM (physical SIM) and a Japanese eSIM simultaneously on a single smartphone. This allows you to receive texts sent to your Korean number while using cheap Japanese eSIM data.
- Pocket Wi-Fi: This is most useful when you need to connect multiple devices like laptops and tablets at the same time, or share data with friends and family. It is also suitable for those who are not tech-savvy, as you only need to connect to the Wi-Fi signal without changing any device settings.
2. Students, WHV Holders, and Long-term Residents: Japanese SIM and Home Wi-Fi
- Japanese SIM (USIM): Essential for long-term residents who need a local Japanese phone number. A Japanese number starting with '070' or '080' is required for address registration, opening a bank account, and applying for part-time jobs.
- Home Wi-Fi: This is the best choice if you want to set up wireless internet throughout your home after renting an apartment in Japan, without complex installation work or long contract commitments.
Solve Your Japan Telecom Worries All at Once with KEICALL
Have you set up your Korean number cheaply with a budget carrier? If so, we recommend KEICALL for your local Japanese data, which offers reasonable rates with no contract burdens.
KEICALL provides customized telecommunication services for students, working holiday makers, tourists, and long-term residents visiting Japan.
- Diverse Lineup: We offer everything from reliable Pocket Wi-Fi anytime, anywhere, to Home Wi-Fi that you can plug in and use immediately without installation, convenient eSIMs, and Japanese SIMs that issue a local Japanese number.
- Reasonable Rates: We greatly reduce your communication cost burden with economical rates starting from around ¥233 per day.
- No Contracts, Zero Cancellation Fees: There are no complicated contract periods, and there is absolutely no cancellation fee (penalty) even if you cancel midway. Those with flexible stay schedules can use our services with peace of mind.
- Convenient Consultation in Korean: Instead of going through complex local Japanese carrier sign-up procedures, you can easily and quickly make inquiries and open a line through familiar SNS channels like KakaoTalk, LINE, and Instagram.
Frequently Asked Questions (FAQ)
Q1. If I move my Korean number to a budget carrier, can I really receive texts for free in Japan?
Yes, that is correct. Receiving standard SMS (short messages) while roaming abroad is basically free, regardless of the carrier. However, please note that charges may apply if you answer or make calls, or when receiving MMS (long/photo messages).
Q2. How do I check if my smartphone supports Dual SIM?
Most relatively recently released smartphones, such as iPhone XS and later models, Galaxy S20, and Z Flip 4/Fold 4 and later models, support the Dual SIM feature, which allows you to use an eSIM and a physical SIM at the same time. Check if there is an option to add an eSIM in your settings under 'About Phone' or 'Network/Cellular.'
Q3. Will my KakaoTalk chat rooms disappear if I use a Japanese SIM?
No. Even if you insert a Japanese SIM or eSIM, your chat history and friends list will remain intact as long as you continue using your existing KakaoTalk app. However, if you reinstall the KakaoTalk app or are asked to re-verify, you must receive a verification code on your Korean number. In this case, you will need to temporarily activate your Korean SIM to receive the verification text.
Q4. Is there really no cancellation fee for the contract-free Japanese Home Wi-Fi?
Yes, KEICALL's Home Wi-Fi and Pocket Wi-Fi services do not have strict mandatory usage periods, and no cancellation fees are incurred upon termination, allowing students and working holiday makers to use them with peace of mind.
Prepare Your Japan Telecom Today with KEICALL!
Now that you have planned how to keep your Korean number, it is time to meet a reliable partner to handle your local Japanese data. Visit the KEICALL Official Website to get detailed information on Pocket Wi-Fi, Home Wi-Fi, eSIM, and Japanese SIMs. Stop worrying about complicated Japanese telecommunications and get friendly, fast consultation via KakaoTalk, LINE, or Instagram!