Who must file a business certificate?

Massachusetts General Laws Chapter 110, Section 5 states that "any person conducting  business under any title or business name other than the real name of the person conducting the business must file a certificate.  A person is defined as an individual, a partnership, or a corporation".

Exemptions to filing are allowed under Section 6 if the corporation is doing business in its true corporate name, or if a partnership is doing business under any title which includes the true surname of any partner.  Certain other exemptions exist for trusts and limited partnerships.