If there are multiple parties, you can serve up to 30 interrogatories to each party. Read the Rule: Md. Rule 2-421(a).Any party may serve written interrogatories directed to any other party. You cannot send more than 30 questions to another party in a circuit court case. The Maryland Rules have form interrogatories that you can use as an example. A party may serve on any other party no more than 25 written interrogatories, including all discrete subparts. If there are multiple parties involved, send copies of the discovery materials and Notice of Service of Discovery Materials to every party. Interrogatories are written questions that require written answers under oath. The other party must answer these questions within 30 days. What are Interrogatories in a Divorce?