A quick search of the web for "register fictitious name in mo" got me to the MO SOS's website. By the answer they are providing, the partnership would need to register the d/b/a/ name because it is neither of the partners' name. If it was Paul Bunyan's Construction, registration would not be required.
What is a fictitious name and why do I have to register?
A fictitious name is a name under which any person or business shall do or transact any business in this state which is other than the true name of such person or business. A fictitious name is commonly referred to as a "DBA", an acronym for "doing business as." Filiing a fictitious name registration does not afford or secure any exclusive rights to the name.
Section 417.200 of the Revised Statutes of Missouri requires anyone doing business under a name other than their true name to file a fictitious name registration with the Secretary of State's office.
Hope this helps.
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