FBA sellers with inventory in Massachusetts establish a physical nexus, obligating them to collect and remit the 6.25% sales tax. However, as Amazon acts as a marketplace facilitator, it handles the tax collection and remittance on behalf of sellers. FBA sellers should ensure their Amazon accounts are correctly set up to utilize this service, maintain accurate inventory records, and monitor sales to confirm Amazon is fulfilling its tax obligations. Additionally, sellers must file periodic sales tax returns through MassTaxConnect, reporting total sales and the taxes Amazon collected, ensuring they meet all compliance requirements while leveraging Amazon’s facilitator services.