Sejong Nuri Call is a special mobility-support service, not a general tourist taxi. The official eligibility page lists people with severe disabilities who have difficulty using public transport, certain people aged 65 or older with long-term-care grades 1-3, certain disabled veterans, pregnant people with qualifying medical certificates, and temporary wheelchair users with qualifying medical documentation.
Registration needs supporting documents and can be submitted in person, by post, fax, email or through the website. The site says screening can take about 3-10 days after documents are complete, so do not assume it can be activated after arrival.
For registered users, the current service page says operation is 24 hours year-round. Bookings from 06:00 to 24:00 can use phone, mobile app or website; from 00:00 to 06:00 the mobile app is used. The fare is KRW 1,000 for up to 3 km, then KRW 200 per additional kilometer, with tolls, parking and waiting charges potentially extra.
The service area includes all of Sejong, including KTX Osong Station, plus Daejeon, Cheonan, Gongju, Cheongju, Chungnam and Chungbuk. Wide-area trips into Chungnam or Chungbuk require phone application by three days before the desired date.
For short-term foreign visitors, the official pages reviewed here do not clearly state automatic recognition of overseas disability documentation. Contact 1899-9042 before travel and ask exactly what documents will be accepted.