The first step in establishing a business in the State of Maryland is to determine which form of business structure is most appropriate for your operations. Guide on MD sales tax for online sellers.Effective March 14, 2021, the Maryland sales and use tax applies to the sale or use of a digital product or a digital code. Easy online tools to register and start a business in Maryland, register a trade name in Maryland and establish tax accounts in Maryland. To file or pay your taxes, visit the Maryland Tax Connect portal, use an independent software provider, or a professional tax preparer. Maryland law not only requires that you display your license but also that you separately state and charge the sales and use tax on each taxable sale you make. Our free online guide for business owners covers Maryland sales tax registration, collecting, filing, due dates, nexus obligations, and more. Maryland online sales tax laws for ecommerce. Gov(link sends e-mail). 410.650.5937.