Kimchi KT Postpaid Plan FAQ — Korea
Answer-first FAQ for KT postpaid (후불) activation with Kimchi Mobile — the plan that carries a real Korean 010 number. Built from a year of real customer questions. This is general information, not legal or immigration advice; rules change, so confirm your own case with the carrier and immigration. For your specific order, ask KIMO in the chat or email [email protected]. See also our Data eSIM FAQ, the guides, and the general FAQ.
Eligibility and the basics
Does KT postpaid give me a real Korean phone number?
Yes. KT postpaid (후불) is the monthly plan that carries a real Korean 010 number registered in your name. This is different from a data eSIM, which is data-only and has no number.
Who can get a KT postpaid number, and which visas qualify?
A Korean number requires a physical Alien Registration Card (ARC / 외국인등록증) and a long-stay residence visa. Long-stay categories that generally qualify include the F-series; E-1, E-2, E-5, E-7, and E-9; and long-stay D-series such as D-2 (student) and D-10 (job-seeker). Tourists, visa-waiver, and short-term visitors cannot get a Korean number and use a data eSIM. If you are not sure your visa qualifies, ask Kimchi before you buy.
Can I get a Korean number on arrival, or on my passport?
No. On arrival you get data, not a number. A real 010 number is issued only after your physical ARC arrives and you convert to KT postpaid. There is no Korean number on a passport or on day one. The registration-fact certificate (외국인등록사실확인서) is not accepted for activation — only the physical ARC card works.
Which SIM do I start with — Welcome SIM or Korea Starter SIM?
Both are the same product mechanically: a 60-day, 60GB data eSIM that bridges to KT postpaid after your ARC arrives. The Welcome SIM is Korvia-exclusive, for people who came to Korea through Korvia. The Korea Starter SIM is the standard equivalent for everyone else. So the question is: did you come to Korea through Korvia? If yes, the Welcome SIM is your option; if not, the Korea Starter SIM is the standard plan.
The application form and documents
How do I apply for KT postpaid? What is the application-form process?
We send you a KT application form to complete. The form requires you to write your name twice, or your name plus a signature — your name and a signature are mandatory. You send back the completed form plus a clean scan of your ID/ARC, your Korean bank account or card details for monthly auto-billing, and your device information (model, storage, and IMEI — dial *#06# to find the IMEI). Kimchi submits your application to the KT activation center, and on approval your KT eSIM QR is issued and your Korean number is set up.
My ID scan was rejected. How do I resubmit it so it passes?
KT’s activation center needs a clean, readable scan. Use a color scan from a scanner or a scanning app on a plain A4 white background, with no glare, in focus, all four corners visible, and not tilted. For an ARC, scan both the front and the back; for a passport, capture the full photo page (a half-page is not accepted). If it keeps getting rejected, contact [email protected] and the team will tell you what to fix.
Timing — when do I get the number?
When is my Korean 010 number issued?
At the moment your KT postpaid conversion is completed — not when you first activate the data eSIM, and not on arrival. The bridge SIM runs on data only until then; the real number is created when you switch to KT postpaid with your physical ARC and a Korean bank account or card in place.
How long does it take after I land?
The ARC is the gating step and commonly takes about 2 to 3 weeks (often longer) after you arrive, because the number cannot be issued without the physical card. Once you have the ARC and a Korean bank account or card, the KT activation itself is typically quick.
Do I need a Korean bank account before I convert?
Yes. A KT postpaid plan bills monthly to a Korean payment method in your name, so a Korean bank account or card must be set up before conversion.
Billing and the 12-month contract
How does billing work, and when is the auto-debit taken?
KT postpaid bills monthly, auto-debited from the Korean bank account or card you submit. The auto-debit date defaults to the 21st of each month; it can be set at activation, and if it is not set it stays the 21st and can be changed later through KT (call 114 or the KT customer center). The KT English Customer Center is 080-448-0100.
Is there a contract discount, and what happens if I cancel early?
KT postpaid is a 12-month contract (약정) that can carry KT’s contract discount (약정할인). Because this is a postpaid activation, Kimchi charges no penalty for the activation itself. However, if you cancel or break the KT contract early, KT (the carrier) may reclaim the contract discount you already received, per KT’s terms — that charge is from KT, not Kimchi Mobile.
Does my postpaid plan auto-cancel after 12 months?
No. After 12 months the line does not auto-cancel — the contract term simply ends, and you must terminate the line yourself if you want to close it. Re-contracting or termination is done with KT (call 114 or the KT customer center; the KT English Customer Center is 080-448-0100). Kimchi is an activation agency and cannot cancel a carrier line on your behalf.
Plan changes, number transfer and leaving Korea
Can I upgrade or downgrade my plan after activation?
You can generally upgrade to a higher-tier plan after activation. Downgrading back to a lower tier is generally not possible once a change is processed. To arrange a change, email [email protected] with your name and Korean number.
Can I keep my existing Korean number (number porting / MNP)?
Yes — number transfer (MNP / 번호이동) is available now. Your current prepaid or postpaid line must be in your own name and must have been activated with your ARC, not a passport. (We are still building the form automation, but number transfer itself works today.) Contact [email protected] to start.
How do I cancel or close my line when I leave Korea?
Settle any remaining balance with KT, then the line is closed. Kimchi is an activation agency and cannot cancel a carrier line on your behalf — final termination is done with KT (call 114 or the KT customer center; the KT English Customer Center is 080-448-0100) — but we can guide you. Tell us your planned departure date and we will help.
eSIM-only and what’s coming
Can I skip the bridge data eSIM and activate KT postpaid directly?
A standalone eSIM activation product, with no prepaid bridge step, is in preparation and is expected around September 2026 — it is not open yet. Until it launches, the bridge plans (Welcome SIM or Korea Starter SIM) remain the path for new arrivals, even if your ARC is already in hand. Contact [email protected] to check the status.
Can Kimchi sell me a phone or a device-installment plan?
No. Kimchi handles eSIM and line activation, not phone sales or device-installment plans. For a handset on installment, that is arranged directly with KT or a retailer. We will still help with the eSIM and the postpaid plan.
Still need help?
Where can I get more help?
Ask KIMO in the chat, or email [email protected] with your name and order or number details. For the bigger picture on who qualifies and how the ARC gates everything, see our Korea SIM card guide and the Data eSIM FAQ.