This research analyzed the feasibility of the Tawau-Polloc Port Cross-Border Special Economic Zone (CBSEZ) under the three-tier regional development corridor framework, which consists of the Greater Sulu Sulawesi Economic Corridor, Southern Mindanao Economic Growth Corridor, and Bangsamoro Development Corridor. The establishment of the Tawau-Polloc Port CBSEZ will integrate the economic regions of Sabah and Bangsamoro Autonomous Region through bilateral trade and investment. The formation of this zone is supported by the respective economic fundamentals and factor endowment between the two regions that complement one another. The implementation of Tawau-Polloc Port CBSEZ will further strengthen the barter trade relationship that has existed for centuries between Tawau and the islands of Tawi-Tawi, Sulu, and Basilan. Tawau-Polloc Port CBSEZ needs to be implemented in stages and in line with the Bangsamoro Development Plan (2014-2019). Tawau-Tawi-Tawi Special Economic Zone is the first initiative in establishing the CBSEZ and it will be extended to Tawau-Sulu, Tawau-Basilan, and eventually to Tawau-Polloc Port. However, there exists a shadow economy in the barter trade relationships between Tawau and Tawi-Tawi, Sulu, and Basilan. This could become a barrier to the implementation of the CBSEZ. Therefore, the laws and regulations under the CBSEZ need to be formulated clearly and transparently to overcome the challenges associated with the shadow economy. An efficient and transparent trade-investment administration would guarantee the success of the Tawau-Polloc Port CBSEZ and have an economic spillover effect on the economy of Bangsamoro and Sabah..