After implementing the Paris Agreement, every member country was required to submit its National Inventory Documents (NID). The South Korean government began estimating and has published National Inventory Reports (NIR) for domestic purposes since 2009 rather than for international reporting. Land Use, Land-Use Change, and Forestry (LULUCF) sector was the only sector including carbon sink and its Greenhouse gas inventory estimation has improved after its first calculation. However, unlike the other categories Settlement could not estimate its carbon balance due to the lack of data. In 2024, Settlements initiated to estimate through building the national data. Therefore, this study aimed to improve more accurate and refined estimations in the Settlements category by reviewing the NID and Common Reporting Table (CRT) submitted to the UNFCCC in 2024. The study determined which of the 43 submitting countries included Settlements in the LULUCF sector. It identified 15 countries estimating Settlements and Settlements Remaining Settlements (SS) and organized them based on consideration of carbon pools. Based on this classification, three representative countries were selected for each Tier of SS, and recommendations for improvement were provided. The representative countries were the Netherlands for Tier 1 and the United States and Japan for Tier 2. According to the investigation of submissions on LULUCF and Settlement categories, four considerations were presented for improving future estimation in the Settlements sector.