D.C. Mun. Regs. tit. 17, § 8908
8908.1 No person carrying on, conducting, or transacting business under any trade name shall be entitled to file an action under that trade name in any of the courts of the District until the person has properly completed the registration with the Department as provided for in this chapter.
8908.2 A person's failure to properly register a trade name shall not impair the validity of any contract or act of such person or persons and shall not prevent such person or persons from defending any suit in any court of the District.
SOURCE: As amended by Final Rulemaking published at 49 DCR 10075 (November 8, 2002).