Call it a privilege tax. It reaches a taxable entity that was formed in Texas or that does business in Texas. Personal income is outside it, and so is a corporate income tax. The state also leaves property tax to cities, to the county, and to school districts.
Margin is the ordinary base, and the EZ computation is the other door when the entity qualifies and chooses it. Four ways exist to compute margin. One multiplies total revenue by 70 percent. One subtracts cost of goods sold from total revenue. One subtracts compensation from total revenue. One subtracts 1 million dollars, and that last way has been available since 1 January 2014.
The federal return, after the exclusions the instructions allow, is where total revenue begins. The bank balance is the wrong starting pile, because a year of deposits also holds loans, owner money, and transfers. None of those three is margin. A monthly close that called them income hands the mistake to this May report.
Cost of goods sold follows its own instructions, and compensation follows another set. Wages count, and so does cash paid to officers, owners, partners, and employees, up to a per person limit, along with certain benefits. A personal expense does not become compensation just because May is close.