§ 15.001.Definitions

Two definitions, and both do heavy lifting.

"Proper venue" is defined in order of precedence. It means the venue required by a mandatory provision — Subchapter B or another statute prescribing mandatory venue — and only if no mandatory provision applies, the venue allowed by the general rule or the permissive provisions. That ordering is the whole architecture of the chapter: mandatory displaces everything, and the general and permissive rules operate in the space left over.

"Principal office" is narrower than people assume. It means a principal office of the corporation, unincorporated association, or partnership in this state in which the decision makers for the organization within this state conduct the daily affairs of the organization. And the section says expressly that the mere presence of an agency or representative does not establish a principal office.

So a company with branch offices in twenty counties does not thereby have venue in twenty counties. The question is where the people who run the Texas operation day to day do so — which is often a single county, and sometimes none if the decision makers are out of state.