Can I list a property that's not located in Texas?

Maybe, but you must consider the licensing law of the other state, Texas licensing law, and the REALTOR® Code of Ethics to determine if the listing is allowed and appropriate.

First, you should contact the state’s real estate regulatory body to determine the restrictions on practice in that state. All states have licensing laws or commission rules that restrict or prohibit the practice of real estate by people not licensed in their state. For example, TREC rules interpret the Real Estate License Act to require that out-of-state brokers be licensed in Texas if they are conducting brokerage business from another state and the property is located wholly or partly in Texas. However, you can cooperate and share commissions with brokers licensed in other states as long as all negotiations within Texas borders are handled by Texas licensees.

While your Texas real estate license permits you to practice real estate while you are physically located within Texas, regardless of the location of the property or your client’s residence, Article 11 of the REALTOR® Code of Ethics states that a broker should not perform a service or handle a transaction for which he lacks the requisite knowledge or expertise. Therefore, even if you are permitted to list the property, it might be better to have a broker who’s licensed in that state help you with the sale or handle the entire transaction through a referral if you aren’t familiar with that state’s laws, contracts, or closing procedures. 

One of my agents is the trustee of an estate located in California. Can he be the listing agent of that estate even though that property is in another state and he does not have a real estate license in California?

Your agent would be best served by contacting a California attorney or the California Department of Real Estate (CDRE), which is equivalent to the Texas Real Estate Commission (TREC) in our state. Each state is responsible for determining the permissibility of an out-of-state agent listing a property for sale. Under Texas law, a person acting under the authority of a will or a written trust instrument does not have to obtain a Texas real estate license in order to sell real property in Texas. Unfortunately, Texas law means nothing in California.