In 2022, the UN initiated negotiations for a global agreement to end plastic pollution, with a mandate to address the full life cycle of plastic products. However, statistics and data on plastics production, composition and recyclability is currently fragmented or lacking altogether, and there is a clear need for improved data and statistics. In February 2024, a Nordic workshop on "Better and Harmonised Statistics on Plastic Material Flows" was organised in Oslo. The workshop gathered technical experts from Nordic statistics bureaus, customs offices, and environmental agencies, with the aim of identifying the most important statistical information to include in national inventories and critical knowledge gaps that need to be overcome in data collection and quality. This report summarizes the discussions and main findings of the workshop.