In Korea, the city bus is one of the most convenient and readily available means of transportation. Throughout the country, city buses provide an easy way to reach any destination, with special colors or numbers to designate each route.

Buses in Seoul are classified by color to differentiate the bus types: blue buses travel on major roads and run for relatively long distances through Seoul; green buses travel shorter distances and carry travelers between transfer points such as subway stations and longer bus routes; red buses are express buses that travel from Seoul to suburban areas; yellow buses operate on a closed circuit within a district of Seoul. Seoul also operates night bus routes, with service from 23:30 until 06:00 the following morning. Promoting this efficient management system, many other regions in Korea have also introduced similar designated bus systems to ensure the punctuality of public transportation.

Bus fare can be paid either by cash or transportation card when boarding. If using a transportation card, passengers can get a transfer discount when changing to the subway system or another bus line. To receive the discount, be sure to tap your card on the card reader by the exit doors before getting off the bus and you must transfer within the time limit which is 30 minutes. However, between 21:00-07:00, the time limit is extended to 1 hour. As passengers paying with cash cannot receive any transfer discount, it is highly recommended to use a transportation card.