In federal court, you can serve interrogatories any time after the parties hold their Rule 26(f) planning conference, and you must serve them early enough that the 30-day response window closes before the court’s discovery cutoff. Those two dates define the entire window.
The Rule 26(f) Conference Is the Starting Line
Federal Rule 26(d) imposes a moratorium on all discovery until the parties have met and conferred as required by Rule 26(f). That conference must happen at least 21 days before the court’s scheduling conference or scheduling order deadline. The parties use it to discuss the dispute, exchange initial disclosures, and build a proposed discovery plan.1Legal Information Institute. Federal Rules of Civil Procedure Rule 26 – Duty to Disclose; General Provisions Governing Discovery No party may serve interrogatories, document requests, or any other discovery before that conference happens.
Older practice let defendants send interrogatories alongside their answer while plaintiffs waited. The modern rules replaced that asymmetry with a single bright line. Once the Rule 26(f) conference takes place, both sides can begin discovery at the same time.
Cases That Skip the Moratorium
A short list of case types is exempt from the moratorium, including actions reviewing an administrative record, petitions for habeas corpus, and proceedings to enforce an arbitration award.1Legal Information Institute. Federal Rules of Civil Procedure Rule 26 – Duty to Disclose; General Provisions Governing Discovery Interrogatories can go out earlier in those matters. The parties can also agree between themselves to begin discovery before the conference, or ask the court for permission to do so. In a typical civil case, though, the conference is the gate.
The Late-End Deadline: Count Backward From the Cutoff
After the parties submit their proposed plan, the judge issues a scheduling order setting deadlines for the case. Federal Rule 16 requires that order within the earlier of 90 days after any defendant has been served or 60 days after any defendant has appeared.2Legal Information Institute. Federal Rules of Civil Procedure Rule 16 – Pretrial Conferences; Scheduling; Management One of those deadlines is the discovery cutoff: the date by which discovery must be complete, not merely sent.
That distinction trips people up. Serving interrogatories on the last day before the cutoff is not timely, because the other side still has their full 30 days to respond. Send questions 15 days before the deadline and the opposing party has no obligation to answer them. A judge almost certainly won’t force the issue either. Count backward from the cutoff: serve your final set at least 30 days ahead, and realistically 45 to 60 days ahead so there is room for objections and any motion practice that follows.
Extending the Cutoff
If circumstances genuinely prevent finishing discovery on time, a party can ask the court to extend the cutoff. Judges evaluate these requests under a good-cause standard and tend to grant them only when the delay wasn’t the movant’s fault. Scheduling difficulties, expert discovery that couldn’t reasonably have been completed sooner, or newly discovered evidence can justify an extension. Procrastination won’t.
Who You Can Serve
Interrogatories can only be served on parties to the lawsuit. Rule 33 is titled “Interrogatories to Parties” for that reason.3Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties If you need information from a witness or anyone else who hasn’t been named in the case, use a different tool, such as a deposition subpoena. Interrogatories to non-parties aren’t allowed.
When the party is a business, government agency, or other organization, an officer or agent must respond on its behalf and must provide whatever information is available to the organization. The organization can’t dodge a question by saying the CEO doesn’t personally know the answer. It has a duty to gather information from across its ranks. Every answer must be in writing and under oath; the person answering signs a verification, and the responses are admissible at trial to the extent allowed by the Federal Rules of Evidence.3Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties
The 30-Day Response Clock
Once interrogatories are served, the responding party has 30 days to provide written answers and any objections.3Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties The clock starts on the date of service, not the date the questions were drafted or placed in the mail.
Delivery method changes the math slightly. When service is by mail or by leaving a copy with the court clerk, Federal Rule 6(d) adds three days, making the effective deadline 33 days.4Legal Information Institute. Federal Rules of Civil Procedure Rule 6 – Computing and Extending Time; Time for Motion Papers Electronic service through the court’s filing system, now the default in most federal courts, does not add those three days. The deadline after e-service is a flat 30 days.
The parties can agree to extend the response time, and judges routinely approve reasonable extensions as long as they don’t push past the discovery cutoff. State court deadlines vary, generally running from 20 to 50 days depending on the jurisdiction, so check the local rules if your case is not in federal court.
The 25-Question Cap
Federal Rule 33(a)(1) caps each party at 25 written interrogatories served on any other single party, including all discrete subparts.3Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties The cap is not advisory. Courts enforce it, and interrogatories exceeding the limit without permission can be struck.
Most disputes arise over what counts as a “discrete subpart.” A single numbered question that asks for the date, location, participants, and outcome of each meeting can be counted as four interrogatories by a court. The test most courts apply is whether each sub-question seeks a distinct category of information. Bundling a dozen questions under one number to stay under 25 doesn’t work and tends to irritate judges.
If 25 isn’t enough, a party can ask the court for leave to serve more. The request has to show that the additional questions are proportional to the complexity of the case and consistent with the scope of discovery under Rule 26(b).3Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties A sprawling commercial dispute with dozens of transactions might justify 40 or 50. A straightforward contract case probably won’t. State courts set their own limits, typically 25 to 30.
Timing Contention Interrogatories
Most interrogatories ask about facts. The rules also permit contention interrogatories, which ask a party to state a legal position or explain how the law applies to the facts, for instance, “State every fact supporting your claim that the contract was breached.” These are proper, but courts have discretion to delay the response until after other discovery is complete or until a pretrial conference.3Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties Forcing a party to lay out a full legal theory before depositions and document production have run their course is often unfair. As a practical matter, contention interrogatories work best when served toward the end of the discovery period, once the factual record has filled in.