SK Telecom (SKT) launched a free USIM exchange service on April 28, 2025, in response to a serious hacking incident that compromised customer information. This service is available at over 2,600 T-World stores nationwide, starting at 10 AM. Customers who subscribed to SKT before midnight on April 18, 2025, are eligible for the exchange.
To manage the expected influx of customers, SKT implemented a 'free exchange reservation system' that became operational at 8:30 AM on the same day. However, the situation quickly escalated into chaos as over 80,000 people were reported waiting in the online system, and long lines formed at T-World locations across the country.
Customers have expressed frustration over the lack of available USIMs, with many reporting that they arrived at stores only to find no stock left. "I came to the store for the USIM exchange but ended up leaving empty-handed," shared one customer who had not received prior notification about the stock issues. This sentiment was echoed across various online platforms, where users lamented the disorganization and lack of clear communication from SKT.
In an effort to assuage concerns over their information security, SKT is also encouraging customers to sign up for the USIM Protection Service, which is designed to offer similar protective benefits. However, this service is also experiencing delays, further compounding customer dissatisfaction.
On April 19, 2025, SKT confirmed that malicious code had led to the leak of some customer USIM-related information, prompting the company to take swift action to protect its subscribers. The Ministry of Science and ICT, along with the Korea Internet & Security Agency (KISA), has initiated an investigation into the incident.
As of now, SKT claims to possess around 1 million USIMs, with plans to secure an additional 5 million by the end of May 2025. However, given the vast number of subscribers—23 million on the SKT network and an additional 1.87 million using MVNO services—there are concerns that this stock will not meet the initial demand.
Store employees have been advising customers to subscribe to the USIM Protection Service while they wait for their exchanges. "We recommend signing up for the protection service to prevent any potential damage while you wait for your new USIM," an employee explained. Despite these measures, many customers are still left frustrated by the long wait times and the unclear guidance provided during the exchange process.
As the situation unfolds, SKT is working to restore its online systems, which have been overwhelmed by the high volume of users attempting to access the reservation portal. On April 28, customers attempting to connect to the T-World app or mobile website were greeted with messages indicating that the services were experiencing delays due to heavy traffic.
"We are aware of the issues and are doing everything we can to resolve them as quickly as possible," a spokesperson for SKT stated. The company is hopeful that with the additional USIMs arriving soon, they can alleviate the current shortages and improve the overall experience for their customers.
Despite the challenges, the launch of the USIM exchange service is a critical step for SKT in rebuilding trust with its customers following the hacking incident. The company has emphasized its commitment to taking full responsibility for any damages incurred as a result of the information leak, stating, "If any harm occurs due to the USIM Protection Service, we will take 100% responsibility." This promise is part of SKT's broader strategy to reassure customers that their security is a top priority.
As the first day of the USIM exchange service continues, many customers remain hopeful that their concerns will be addressed and that the service will stabilize in the coming days. With the promise of additional USIMs and improved online functionality, SKT aims to restore normalcy and confidence in its services.
In summary, while the launch of the USIM exchange service was met with significant challenges, SKT is actively working to resolve these issues and ensure that customers can access the support they need. The situation highlights the importance of effective communication and preparedness in managing customer expectations during a crisis.
