In some cases, for example if you will be selling goods and collecting sales tax, you’ll need to register with the Texas Comptroller of Public Accounts. (Texas also imposes an annual franchise tax on most LLCs.) Depending on the tax involved, you may be able to register online, by mail (using the correct form), or in person at a Comptroller field office. For more information on state LLC tax registration, see Nolo's article Texas LLC Annual Filing Requirements.