27 CFR 555.56: Change in trade name.

A licensee or permittee continuing to conduct business or operations at the location shown on his license or permit is not required to obtain a new license or permit by reason of a mere change in trade name under which he conducts his business or operations. However, the licensee or permittee shall furnish his license or permit and any copies furnished with the license or permit for endorsement of the change to the Chief, Federal Explosives Licensing Center, within 30 days from the date the licensee or permittee begins his business or operations under the new trade name.