About 80,000 subscribers have left KT since it began waiving termination fees on the 31st over the unauthorized micro-payment incident.
According to the telecom industry on the 6th, a total of 79,055 subscribers left KT via number portability over six days from the 31st to the 5th. Of these, 26,394 people switched to other carriers on the 5th alone, when number-porting requests from Sunday the 4th, when mobile service activations are not processed, were counted together. In particular, 80% of the number-porting subscribers that day moved to SK Telecom. Including mobile virtual network operators, 73.5% of customers leaving KT chose SKT.
The number of customers leaving KT was 10,142 on the 31st, when the termination fee waiver began, and totaled 21,492 on the 2nd (two days including the holiday on the 1st). On the 3rd, the first weekend since the waiver took effect, 21,027 people left KT. The exodus from KT is expected to continue.
According to the industry, on the morning of the previous day, "response timeout exceeded" errors occurred during number portability processing from KT to SK Telecom and LG Uplus, causing delays for a time. The disruptions continued into the afternoon, and activations did not proceed smoothly. Some customers had to postpone activation to the next day. The Korea Telecommunications Operators Association (KTOA), which runs the system, explained that delays occurred as number portability requests accumulated over the weekend were processed at once. Last year, during a period when subscriber departures were concentrated at SK Telecom, the number portability network also did not operate smoothly. At that time, amid suspicions of number portability restrictions, the Ministry of Science and ICT launched an investigation. An industry official said, "Had errors not occurred, more than 30,000 people would have left KT on the 5th."
On the 30th, KT held a press briefing on "apology to customers and information security innovation plan regarding the breach incident" and said it would fully waive termination fees for customers canceling mobile service. The application period is two weeks from that day through Jan. 13, 2026, and it will be applied retroactively to customers who already canceled between Sept. 1, 2025, and Dec. 30. Termination fees will be refunded after a customer applies.
Rival carriers are aggressively engaging in subscriber acquisition marketing to attract customers. SK Telecom is restoring the length of service and membership tier to their original status if customers who canceled after last year's hacking incident return. In addition, for customers who port numbers or newly subscribe this month without buying a device, it offers a full refund of the first month's bill and free benefits such as online video service (OTT) and webtoons. SK Telecom is also said to have notified select retail channels of a special promotion to pay a sales incentive of at least 300,000 won for each "USIM-only" port-in subscriber secured.
From Dec. 31 last year, when KT began waiving termination fees, to the 5th, the total number of number portability transactions came to 198,190. As competition among carriers intensified and companies put money into marketing expense, the total number of number portability transactions reached 63,702 on the 5th. The totals were 35,595 on the 31st, 54,744 on the 2nd (two days including the holiday on the 1st), and 44,149 on the 3rd.
An industry official said, "The surge in number portability is expected to continue until the 13th, when KT's termination fee waiver ends."