§ 2030.020.Time to propound interrogatories; motion for leave to propound at earlier time

This section answers a timing question that comes up in nearly every case: how soon can a party start serving written interrogatories? A defendant faces no waiting period at all and may propound interrogatories to a party at any time after the action begins. A plaintiff faces a short buffer instead, interrogatories may go out once 10 days have passed since the summons was served on, or the party appeared in the action, whichever happens first. That same 10-day rule carries over to unlawful detainer actions and other summary proceedings to recover possession of real property, even though those cases move on a compressed overall schedule.

Subdivision (d) gives a plaintiff who cannot wait out the 10 days a way around the rule: on a motion, with or without notice to the other side, the court may grant leave to propound interrogatories earlier on a showing of good cause. That mechanism matters most in fast-moving cases, an unlawful detainer proceeding heading to trial in weeks, or a case where evidence is at risk of disappearing, where the standard 10-day buffer would eat into a plaintiff's already short window to gather information before trial.