Tanzania has invested heavily in sustainable management of its octopus fishery, including community-based reef closures and industrial processing systems, and also in increasing access to export markets. Despite these efforts, significant losses still occur along the value chain, particularly at the landing, aggregation, transportation and processing stages. Annual postharvest losses (either in weight or from lower quality) and accumulated hidden losses are estimated at USD 295,000, which reduces incomes across the value chain actors. Annual losses in government revenue are estimated at USD 154,500, mainly derived from processing, underreporting, lower quality and rejected export products. Reducing even 50% of these losses could recover approximately USD 148,000 annually for value chain actors and USD 77,000 in government revenue, increasing income and supporting Tanzania’s blue economy and sustainable fisheries goals without raising fishing pressure.