When can a defendant file a motion to dismiss in California for failure to respond discovery?

You can file at any time, but it's not likely to be granted until a hearing. Basically plaintiffs do this all the time. They do not have to produce verification until the hearing.

Thanks for your answer. I thought that the law in California permitted to file a motion to dismiss with prejudice after 30 calendars days of sending them a discovery interrogatory with certified/signature return mail. This is in California.

Now what would happen if I did not answer their discovery in the same amount of time after being served? Would all answers be deemed accepted. Thank You for your answer.