Texas: a revenue-based measure with a reporting duty. The Texas franchise tax applies to each taxable entity formed or doing business in Texas and is based on the entity's "margin": total revenue reduced, at the entity's choice, by cost of goods sold, by compensation, by 30 percent of revenue, or by a flat deduction. There are separate rates for retail or wholesale businesses and for others, and a simplified computation for smaller entities. An entity at or below the no-tax-due threshold still files: it owes no tax but must file its Public Information Report or Ownership Report. The annual report is due May 15. An entity that misses its filing receives Form 05-211, a notice of intent to forfeit the right to transact business in Texas.
California: a flat minimum, and a different name for LLCs. The Franchise Tax Board states that every corporation that is incorporated, registered or doing business in California "must pay the $800 minimum franchise tax", and that newly incorporated or qualified corporations, since January 1, 2020, are not required to pay it in their first taxable year. For LLCs the FTB uses different words: every LLC doing business or organized in California "must pay an annual tax of $800", and the first-year exception for LLCs applied only to tax years beginning in 2021 through 2023.
Delaware: the state of incorporation charges too. A Delaware corporation files an annual report and pays its franchise tax by March 1 for the prior year, figured under either the Authorized Shares Method or the Assumed Par Value Capital Method, and an LLC, limited partnership or general partnership pays a separate annual tax instead. A company that incorporates in Delaware and operates elsewhere can therefore owe Delaware's tax and the operating state's charges as well.
Why the federal government cares. Interest on Treasury securities is exempt from state and local taxation under 31 U.S.C. 3124(a), but that section carves out "a nondiscriminatory franchise tax or another nonproperty tax instead of a franchise tax, imposed on a corporation." So a state franchise tax on a corporation, measured by income, can count Treasury interest that a state personal income tax could not reach.
Entity choice does not escape it. A single-member LLC is disregarded for federal income tax and reports on the owner's Schedule C, but California's annual LLC tax applies to every LLC organized or doing business there. The state charge is a cost of the entity, so it belongs in the comparison whenever an owner weighs forming an LLC or corporation against operating as a sole proprietor.