SK Telecom and other SK Group ICT affiliates ranked No. 1 across all telecom service categories in the Korea Service Quality Index (KS-SQI), including mobile, broadband internet, internet TV (IPTV), international calls and MVNO services.

SKT said on Wednesday it ranked first in the mobile category in the 2026 KS-SQI survey organised by the Korean Standards Association, keeping the top spot for a 27th straight year. KS-SQI is an index created by the Korean Standards Association by surveying customers who used the products and services of domestic companies and quantifying satisfaction across eight areas, including expertise, sincerity, proactiveness and social value.

SKT has ranked first in the mobile category every year since the KS-SQI survey began in 2000. It said SKT is the only company across all industries to achieve a 27-year streak at No. 1.

SKT has improved services at customer touchpoints such as its distribution network and customer centres and has pursued activities to strengthen customer trust since last year's cyber intrusion incident. It has met directly with customers of more than 40 years to hear their views, shortened consultation procedures and assigned dedicated counsellors to make it easier for long-term customers to use customer centres. It is also reflecting requests gathered through independent advisory bodies such as a customer trust committee and a customer advisory group.

It also expanded customer benefits. It announced in May measures to strengthen benefits by simplifying complex bundled rate-plan structures and providing basic data even after customers use up their data allowances. Through Aug. 21, it will increase roaming data allowances for the holiday season and run a "first roaming 70 percent discount" promotion for customers in their 20s and 30s.

Under its T Membership programme, it runs a monthly "Young Week" for customers aged 13 to 34. It also plans to hold invitation events in dining, performances and entertainment through year-end under "T Long-term Customer Day" for customers with at least 10 years of membership.

In the social value category, it operates an AI care service that supports welfare checks, emotional care and emergency rescue for vulnerable groups. It also provides a care support service that uses vision AI technology to recognise and analyse the behaviour of people with developmental disabilities in real time. It also runs the "Happiness AI Coding School", where employees serve as instructors to provide AI education to teenagers with disabilities. It plans to provide education to 160 schools and about 5,000 people by the end of this year.

SKT is also enhancing AI-based network security and spam and voice-phishing blocking technology. In the first quarter of this year, it blocked about 186 million cases of voice phishing and spam. It recently published its first information security white paper, "Information Security White Paper 2025", and disclosed its information security activities and measures to strengthen customer protection.

SK Broadband posted No. 1 rankings for a 12th straight year in broadband internet and an eighth straight year in IPTV. SK Telink also ranked first for an 18th straight year in international calls and for a fourth straight year in the MVNO category.

Jae-heon Jeong (정재헌), SKT's chief executive, said receiving customer support and trust for 27 years in the KS-SQI survey is an achievement he would not trade for anything. He said SKT will do its best in activities to strengthen customer trust so customers can use its services with peace of mind and feel proud.