Yes, dropshipping is perfectly legal. However, you must ensure that your business is properly registered to be dropshipping online.
For every state that requires you to collect sales tax you will need to obtain a resale certificate by registering with your State’s Department website (see links below). With most states you are generally going to look for a section called “Sales Tax” or sometimes “Sales and Use Tax”. There should be some kind of registration form that you will need to fill out in order to obtain your resale certificate or permit. Once you have that you will legally be able to collect sales tax from your customer and remit it to the appropriate state. Until you have this step completed, we do not recommend making your first sale.
Register your dropshipping business with your State
NOTE: If you intend to register your business as a corporation or LLC you will not be able to register until you register with the Secretary of State for the state your business will be structured.