Legal Question in Family Law in California

By doing business in California, they subject themselves to California subpoena power. Use the California forms. They also must appoint an agent for service of process in California. For probably 90% of the major national corporations that agent is a service called CT Systems. You can look it up on the Secretary of State's website to make sure that is the correct agent for TD Ameritrade. Once you identify the correct agent for service, my policy and practice is to formally serve the agent, but send a copy to the company at the address they prefer as well. Companies that size have whole departments devoted to nothing but complying with third-party subpoenas. You will get faster results and less chance of "lost in transit" if you send a copy directly to where they say.