International flights connect Kota Kinabalu (KK) to the world with AirAsia (www.airasia.com), Malaysia Airlines (www.malaysiaairlines.com), Jetstar (www.jetstar.com) and an increasing number of Asia-Pacific carriers. Between AirAsia and Malaysia Airlines, a web of flight routes connects Kota Kinabalu to every major city in Borneo, including Bandar Seri Begawan (Brunei).
There are seasonal charter flights from Taiwan to Sandakan, and plans to turn Sandakan Airport into a proper international airport.
It's possible to fly to Tawau from Tarakan, Kalimantan, with MASWings (www.maswings.com.my).
It is possible to travel to Tawau by boat from Kalimantan (Indonesia). From Brunei there are car ferries to Menumbok and the Malaysian federal district of Pulau Labuan, linked to KK by ferry. A new ferry route from Kudat to Palawan in the Philippines is due to launch by 2019, and there are weekly ferries from Sandakan to the troubled Philippine island of Mindanao.
Buses link Brunei with destinations along Sabah's northwestern coast and KK. If travelling overland from Sabah to Sarawak, you have to change buses in Brunei.