Establishing a physical presence in Massachusetts—such as opening a retail store, maintaining inventory, having offices, employing staff, using delivery vehicles, or hiring independent contractors—creates a nexus, obligating businesses to collect and remit the 6.25% sales tax. This physical presence signifies a significant economic relationship with the state, requiring businesses to register with the Massachusetts Department of Revenue, charge the appropriate tax on taxable sales, and comply with regular filing and remittance obligations. This ensures that businesses contributing to the local economy also support state revenue through tax collection.