In Delaware you can file your DBA (aka trade name, assumed name or fictitious business name) yourself with your Prothonotary�s Office in the Superior Court for the particular county you are going to be doing business in. . Or, use a legal document service such as LegalZoom to handle the entire process for you.
LegalZoom charges $99.00 (plus state filing fees) for Delaware DBA’s. Click here to learn more about pricing.