If KT’s online eSIM device-change flow rejects the request, keep the old phone and line working while you identify the exact failure. Do not delete the installed eSIM, assume its QR code can be reused, or move another person’s SIM into the new phone. The practical recovery route is tied to the current customer’s KT account, line, device, and error.
Record the state before changing anything
Save the line number, plan name, account holder, old and new phone models, and the error shown on screen. On the new phone, record the EID and IMEI and connect it to Wi-Fi. Check whether the old phone still has calls, messages, and data, and whether its eSIM profile is still installed.
The current KT eSIM move guide separates several cases. An eSIM-to-USIM change requires a USIM prepared in advance, while supported eSIM moves depend on the handset and authentication path. For a Dual Number setup, KT says to change the main line first, change the Dual Number line separately, and then restore their relationship. Treat those as separate recorded states, not one automatic transfer.
This article concerns a resident customer’s existing KT line. A prepaid tourist profile can follow a different seller policy; use the tourist eSIM deletion and phone-change guide for that separate case.
An online rejection does not define every device-transfer method
KT’s published eSIM device-change certification page lists foreign customers among the users directed away from that online service to a nearby KT dealer or plaza. This published notice does not establish that every operating-system transfer feature is unavailable to every foreign customer. It also does not guarantee that a store will accept a particular document, model, account condition, or request.
The online move guide supports listed Korean-market Samsung devices and listed Korean or overseas Apple devices; it excludes overseas Samsung devices from that online route. An IMEI registration restriction or a data-sharing secondary line also sends the customer to a dealer or plaza. Check the exact model and line type first. Ask that location which identity and account records it requires for your case, and whether it handles that device. Do not use another person’s account, SIM, password, or identity as a workaround.
Keep the old line until activation is confirmed
For supported moves, KT instructs the customer to use Wi-Fi on the new device; its certification page says the old phone’s hotspot cannot be used for the eSIM download. Some two-device flows also require the old device. The page warns that calls and data on the old phone stop after activation. Keep the old device charged and accessible through the confirmed procedure, then test outgoing and incoming calls, messages, and data on the new phone.
The online page lists a KRW 2,750 eSIM issue charge including VAT, billed later. That does not prove a store will charge the same amount or that every failed request creates a fee. Ask which action was actually completed and which charge applies before paying again.
Device insurance is a separate record. KT says insurance can remain attached to the old handset after a device change and directs customers who want to end it to customer service at 100. Do not assume the new phone became insured or that the old policy ended with activation.
If the old phone or profile is already unavailable
If the phone was lost, the eSIM was deleted, or the old device cannot complete authentication, stop retrying unverified QR codes. Take the owner’s line and account records, the new phone’s identifiers, and any saved error to KT and ask it to identify the available recovery or replacement route. If the line cannot make a call, use a call-capable phone while the customer remains involved in their own case, or go to the confirmed handling location.
Ask KT to state the result before you leave: which device now uses the line, whether the main and Dual Number relationship is restored, whether the old line has stopped, what fee was recorded, and what happened to the old-device insurance. Recovery of the same number, foreign-customer admission, English help, document acceptance, and model approval are not guaranteed by the public pages.
KT eSIM move and device-change certification pages checked October 6, 2026 KST. Confirm the current line, model, account, handling location, and activation result for the actual request.