A trade name, trading name, or business name is a pseudonym used by companies that do not operate under their registered company name. The term for this type of alternative name is a "fictitious" business name. Registering the fictitious name with a relevant government body is often required.
In a number of countries, the phrase "trading as" (abbreviated to t/a) is used to designate a trade name. In the United States, the phrase "doing business as" (abbreviated to DBA, dba, d.b.a. or d/b/a) is used, among others, such as assumed business name or fictitious business name. In Canada, "operating as" (abbreviated to o/a) and "trading as" are used, although "doing business as" is also sometimes used.
A company typically uses a trade name to conduct business using a simpler name rather than using their formal and often lengthier name. Trade names are also used when a preferred name cannot be registered, often because it may already be registered or is too similar to a name that is already registered.
Legal agreements (such as contracts) are normally made using the registered legal name of the business. If a corporation fails to consistently adhere to such important legal formalities like using its registered legal name in contracts, it may be subject to piercing of the corporate veil.
In English, trade names are generally treated as proper nouns.