KT Japan SIM Business
SIM Business
We provide high-quality communication with official SIM cards from KT, Korea's No.1 carrier. Our Korean information platform 'tt shop' offers great deals for Korea travel.
Market Leader
Korea's No.1 Carrier eSIM/USIM Cards
Since 2019, we have been selling KT SIM cards for Korean local data communication. We sell KT eSIM/USIM through various channels.
Instant Delivery
Within 1 Hour
Short-Term Travel SIM
We sell eSIMs with unlimited calls, SMS, data, and a Korean 010 number on 2 to 15-day plans, perfect for Korea travel and business trips. Issued online immediately after purchase for instant use.
Worry-Free Korea Travel
Stay connected with high-speed 4G/LTE data from the moment you arrive in Korea.
- check_circleUnlimited Calls, SMS & Data
- check_circleKorean 010 Number Included
- check_circleeSIM
- warningSIM unlock required
Price Plans
30% OFF
2 Days
¥1,050
¥1,500
15% OFF
3 Days
¥1,450
¥1,700
20% OFF
4 Days
¥1,750
¥2,200
24% OFF
5 Days
¥2,050
¥2,700
20% OFF
6 Days
¥2,400
¥3,000
24% OFF
7 Days
¥2,600
¥3,400
21% OFF
10 Days
¥3,000
¥3,800
12% OFF
15 Days
¥3,950
¥4,500
eSIM Information
QR code delivered instantly via email. No physical card needed. Shipped within 1 hour after payment.
USIM Card
Physical SIM Card (3-5 Days)
Use your USIM card as soon as you arrive in Korea. Unlimited calls, SMS, and data included.
For Long-Term Stays
Long-Term Stay SIM
20 to 90-Day Long-Term Plans
Plans designed for study abroad, business trips, and extended travel. Unlimited calls, SMS, and data with a Korean 010 number included.
12% OFF
20 Days
¥4,500
¥5,100
13% OFF
30 Days
¥5,200
¥6,000
11% OFF
60 Days
¥8,900
¥10,000
12% OFF
90 Days
¥11,500
¥13,000
Phone plan for studying in Korea
Phone, SIM & eSIM for Studying in Korea: "Welcome 5G" A Postpaid Plan You Can Apply for in Japan Before Getting Your ARC
If you are moving from Japan to Korea for long-term study, we recommend KT's postpaid plan for students, "Welcome 5G." You can apply while still in Japan and start using a Korean phone number (010) right after you arrive. Both a physical SIM (USIM) and an eSIM are available. Your number stays the same after your Alien Registration Card (ARC) is issued, so you can move straight on to Korean identity verification. There is no minimum contract and no cancellation fee.
Why students in Korea need a phone plan
In Korea, everyday services such as website sign-ups, opening a bank account and food delivery apps ask for identity verification using your mobile number.
Usually you sign up for a prepaid SIM, wait for your ARC, then switch to a postpaid plan — and your phone number changes when you switch. With Welcome 5G you start on a postpaid plan from day one, so your number never changes.
Welcome 5G plans (monthly)
Welcome 1
1GB + unlimited at up to 1Mbps after
200 min calls / 200 SMS / 001 Free
₩39,000
Welcome 3
3GB + unlimited at up to 3Mbps after
200 min calls / 200 SMS / 001 Free
₩49,000
Welcome 5
5GB + unlimited at up to 5Mbps after
200 min calls / 200 SMS / 001 Free
₩59,000
※ Monthly fees include VAT (KT official, as of October 2026). When tethering or sharing data with other devices, usage is limited to the base data allowance.
4 key features of Welcome 5G
Apply in Japan in advance
No need to wait for your ARC — use the postpaid plan right after you arrive.
Same number for identity verification
Just register your details once your ARC is issued. Your number never changes.
No contract, no cancellation fee
Cancel when you return home with no penalty (we recommend using it for at least 4 months).
Calls to Japan with "001 Free"
Call your family in Japan from Korea by dialing international calls with "001."
STEP 1 | Before arrival (in Japan)
Documents you need to apply
- Application form
- Scan of your passport
- Proof of enrollment (e.g., letter of admission)
- Three alien registration application forms (all completed in English)
※ Please submit clear scanned files (PDF, etc.), not smartphone photos.
STEP 2 | After arrival
Submit your ARC
Submit your Alien Registration Card once it is issued. If it is not submitted within 3 months of arrival, the line will be cancelled.
Your bill arrives by SMS around the 5th–10th of the following month. You can pay by transfer from a Korean bank account or at a convenience store in Korea.
FAQ: phones for studying in Korea
Can I use my Japanese smartphone in Korea?expand_more
Yes. If your smartphone is SIM-unlocked, just insert the KT SIM and use it as is.
Can I get a Korean phone plan without an Alien Registration Card?expand_more
Welcome 5G can be applied for while you are still in Japan, so you can use the postpaid plan right after arrival. Submit your ARC within 3 months of arrival once it is issued.
Does Welcome 5G have a minimum contract or cancellation fee?expand_more
There is no minimum contract period, and no fee if you cancel when you return home. We recommend using it for at least 4 months.
What happens when I use up my data?expand_more
After the base data is used up, Welcome 5 continues at up to 5Mbps, Welcome 3 at up to 3Mbps and Welcome 1 at up to 1Mbps, with no data cap.
How do I pay?expand_more
Your bill arrives by SMS around the 5th–10th of the following month. Pay by transfer from a Korean bank account or at a convenience store in Korea.
Is Welcome 5G available as an eSIM?expand_more
Yes. Welcome 5G is available as both a physical SIM (USIM) and an eSIM. If your unlocked phone supports eSIM, you can choose eSIM.
Can I call Japan from Korea?expand_more
Yes. With "001 Free" you can make international calls by dialing with "001."
For short-term study of 90 days or less, the Long-Term Stay SIM (prepaid) is also available.
Ready for Your Trip?
Purchase a SIM now on tt shop, or consult our experts about custom business solutions.