Legal Question in Real Estate Law in California

You don't need the landlord's permission when you have a court order in your hand. Is the landlord a party to the lawsuit? If so you should contact his/her attorney about responding. If the landlord is not a party, make sure they were served with a copy of the subpoena. You can object to appearing if the landlord was not given a "notice to consumer" unless the landlord's regular business is being a landlord.

Other than that, it sounds like you have to go. You are entitled to mileage and a small witness fee. They must pay it to you before starting the deposition. The deposition can take place any time that is at least 20 days after the subpoena is issues, and 15 days after it is served, whichever is later. So it sounds like they served you with plenty of time under the law.

I would differ with Mr. McCormick about the 20/15 day time requirements. Those are for a different kind of subpoena. Code of Civil Procedure 2020.220 specifies "a reasonable time" for prior notice for a records-plus-testimony appearance.

Depositions in general are subject to mileage restrictions, and I think they are the same whether a party is to be deposed upon notice or a nonparty uinder subpoena (but I'm not sure of this without looking it up, and I'm at home). At the election of the person taking the deposition, it can be taken (1) within 75 miles of your home and in any county, or (2) if taken within the county where the suit is pending, the deposition can be taken within 150 miles of your home. Note that the mileage is measured between your home and the place where the deposition will be taken not the courthouse (unless, of course, that's where the deposition will be taken.

The fees and mileage you will receive are rather modest and are set by the Government Code.

The statutory language about subpoenas affecting consumer records might apply, but I am somewhat doubtful; it is found in tha Civil Code at Section 1985.3.