In an action of assumpsit to recover for work done and materials furnished, an affidavit of defense which sets forth that the plaintiffs were carrying on a business under a fictitious name and did *Page 524 not file in the office of the secretary of the Commonwealth and in the office of the prothonotary, a certificate, under oath, as required by the Act of June 28, 1917, P. L. 645, is sufficient to prevent judgment.
The Act of June 28, 1917, P. L. 645, provides that "no individual or individuals shall hereafter carry on or conduct any business under any assumed or fictitious name unless the person or persons carrying on the same shall have filed in the office of the secretary of the Commonwealth and in the prothonotary's office a certificate, under oath, signed by said person or persons setting forth the real name or names of all such persons interested in the business and also the name under which the business is being or will be conducted. The third section of the act makes the carrying on of any business in violation of this section of the act a misdemeanor.
Where the plaintiffs were conducting a business under a firm name, which was not registered, they were guilty of a misdemeanor. The account against the defendant was contracted in the prosecution of that business, and it was part of the business in which they were engaged and for which the firm was organized. An action founded on a transaction prohibited by statute cannot be sustained, although it be not expressly declared in the statute that the contract is void. Whenever it appears that the action is founded on the violation of a statute, the obligation is invalid.