Market access effects for ASEAN countries under an ASEAN-EU Free Trade Agreement were investigated. The researchers created new ways to measure how easily goods can enter markets. They found that current market access for select ASEAN countries is reduced by half because of EU preferences given to competing nations. Also, the preferential margins granted by the EU are usually for products making up less than 0.1% of exports. Furthermore, about a quarter of the preferential benefits in the proposed agreement would be lost due to preferences granted to ASEAN GSP members. Lastly, the rules for product origin are stricter for goods with higher preference margins. This research offers insights into how trade deals impact the competitiveness of ASEAN countries in the EU market.