How To Transfer to eSIM: Lessons From SKT SIM Breach

by Rian

Though the title may sounds like a proper how-to, I ended up deciding to write it as “documentation” of what happened in my particular case. It obviously won’t work for everyone, and your mileage will vary greatly. I believe the common core issues for everyone would be that nearby carrier stores would not have enough physical SIM cards to serve all the affected customers, roughly 23 millions, so we are being waitlisted. Unless you absolutely do need a physical SIM card, you can apply for transfer to eSIM. This post covers staying in the same contract, but changing the carrier network is also an option. If you were using a physical SIM prior, checking whether or not your device supports eSIM is mandatory: any iPhone since XS (2018) had eSIM support, and Galaxy had eSIM support since S23 (2023).

Solutions

Both iPhone and Apple Watch can have its eSIM re-issued from SKT website. In my case, I had my “USIM” or physical nano SIM card transferred over to eSIM.* The process took roughly 5 minutes per device on T Direct Shop, and from my experience, I do recall some cellphone plans cannot be ported over to eSIM back when eSIM first started. I do not know if SKT has finally lifted the policy since or has updated its system to allow it.

*The same form I used for Apple Watch should work for regular phone lines as well, so you could try using it if you are re-issuing eSIM (i.e. eSIM to eSIM), instead of transferring from physical SIM to eSIM.

Before you do start the process, “USIM Protection Service” from SKT has to be disabled temporarily. The transfer itself requires IMEI and EID of your phone. To be exact, IMEI for physical SIM, another IMEI for eSIM, and EID. They are all available on Settings > General > About. It can be copied over with a long press, so don’t panic over the long digits of numbers.

On Apple Watch’s side, initially the documentation seems to suggest re-issuing eSIM —Apple Watch doesn’t have physical SIM slot— can’t be done remotely. I was able to find a solution online. Deleting the eSIM from Apple Watch is relatively straightforward; it must be done from the Apple Watch app. From Watch app > Cellular, click the “i” icon next to the carrier name, and it will give you a choice between managing the account and deleting it. Choose to delete it. It may take awhile.

There is a form on T World for a change of eSIM, which apparently simply translates to re-issuing eSIM for a device. And it was for me; I don’t think the carrier is issuing identical eSIM, as it says it will be caring 2,750 won in fine print.

The online form from SKT would ask for the “phone number” of your Apple Watch, which is available on T World > My, then click “Show Masked Information” on the upper-right corner. Now your current main line phone number should be unmasked on the webpage. Click the link, and it will create a pop-up with your Apple Watch line phone number in it. That’s the number for the form. Once the form is completed, it will automatically start downloading an eSIM to your Apple Watch.

I restarted both of my devices just in case after eSIM installation was over. Activation took longer on Apple Watch, so I was worried at first it might be stuck; after the restart, it was already connected and connecting to the network without any issues.

Afterthoughts

I can’t add much valuable information on what must be happening behind the curtains. It’s all speculations currently, and I don’t have much else tips on what went on. There are rumors that if you are not using freely available “USIM Protection Service”, the Korean carrier might fight against customer compensation. I’m not a lawyer and this is not a legal advice, but it would be a likely strategy; it would also help for your own security to use the free service.

What confuses me though is their inconsistent phrasing and documentation. For example, the text message I just received from SKT says “if [you] reserve to be on [USIM Protection] ‘Service’”; does it mean signing up online doesn’t activate the protection service right away? Why is there a waitlist?

And if SKT had not botched its initial eSIM introduction in 2022, the actual carrier stores wouldn’t be overrun with physical SIM card-holding customers. And if SKT had more thorough documentation on eSIM and the level of accessibility to eSIM online, the company could have remedied the problem much quicker.

One last bit of information I can share is that the English version of T World website is not well maintained compared to the Korean. The current featured banner for Korean version of the website is on the recent security breach with pop-up notice of same subject, whereas the English version isn’t. The Korean version of the same website is far more resourceful, so I would recommend using that instead. Best of luck for everyone who is going through this and for the employees in the front line who must be equally puzzled.