A DBA is not a legal entity, but whether you have a DBA or not, you must file taxes. Your company's formal business structure determines the frequency with which it must file taxes. Sole proprietorships file annual tax returns. Partnerships, LLCs, and corporations file yearly tax returns with the IRS, but they may also be required to pay quarterly taxes if they anticipate owing taxes at the end of the year. Businesses must also file state tax returns; some states may require quarterly or annual filings.