You must register separately in each county where you will do business. Go into the Prothonotary's office listed below to fill out the form and do a name search to be sure your chosen name hasn t already been used. They will show you how. Doing this will protect your trade name from use by others in each county where registered. Also, they could lose use of the name to whoever properly registered it.
Some banks require registration of names by business customers.
Sussex Co. Court House Rm. 211 Georgetown 5. If the business is located in a town or city, call the local government to determine local business requirements. Call the SBDC or the Delaware Dept. of Labor for help. Yes, if your business, especially a consumer business, uses a name or symbol worth protecting and it may someday sell beyond the local area.