The Korea Customs Service (KCS) said the understanding was reached at the 11th annual meeting of South Korea-ASEAN customs chiefs in Brunei on Thursday.
The 10-member economic bloc represents the second-largest export market for locally made goods after China, but companies taking full advantage of the free trade agreement reached in 2005 stood at just 37 percent as of 2014.
In the first four months of 2015, exports to ASEAN reached US$38.55 billion. In the same period shipments to China stood at $45.66 billion, while numbers for the United States hit $23.58 billion
At the gathering, the trading partners agreed to work closely to follow through on the Agreement of Trade Facilitation reached by the World Trade Organization in November and pledged to push forward the signing of an authorized economic operator system and mutual recognition arrangement, the service said.
Both systems are designed to give preferential clearance to products made by companies that have a track record for transparent customs reporting.
The KCS also said it plans to offer assistance to ASEAN countries to better train customs officials.