Easy online tools to register and start a business in Maryland, register a trade name in Maryland and establish tax accounts in Maryland. Here are some things you need to know and do to comply with your responsibilities as a new Maryland business.Complete a Combined Registration Application. You can apply for a business license through Maryland Business Express Online. This article provides a stepbystep guide to starting an LLC in Maryland, including the cost. All retail vendors are required to register and collect the. Maryland sales and use tax and obtain a sales and use tax license. 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. Buying or selling a Maryland business? Starting a business in Maryland?