The requirement of a fictitious name registration is state pecific. In Connecticut doing business under an unregistered trade name/fictitious name is an unfair trade practice. In Connecticut violation of the Unfair Trade Practice Statute can render a defendant liable for double and in some cases triple damages as well as payment of the plaintiff's attorney's fees.

I recently won an arbitration in New York in which the defendant's corporate identity was not verifiable and in effect had become a fictitious name. Nowhere could any form of registry be ascertained. He also failed to identitfy the name of the user of the fictitious name and whether he was acting as agent on the contract. He was caught with all the damages awarded.