Will AI Replace Lawyers? The Future of Legal AI
Interrogatories vs Deposition: Federal Rules Compared
Interrogatories vs Deposition: Federal Rules Compared
Legal content overseen by Nathan Walter, Esq., attorney licensed in California (State Bar No. 313299).
In federal civil discovery, interrogatories are written questions served on another party under Rule 33(a)(1). An oral deposition examines a person under oath or affirmation, with live follow-up questions (Rule 30(a)(1), (c)(1)).
Both operate within the limits of Rule 26(b)(1), but the recipients, response format and procedural defaults differ. The distinction matters when you need information from a party rather than testimony from a particular person.
This interrogatories vs deposition comparison covers U.S. district-court practice under the Federal Rules of Civil Procedure (FRCP) and is written for plaintiff-side teams. For the full response process, see our federal interrogatories guide.
Interrogatories vs Deposition at a glance
The deposition column below describes an oral deposition under Rule 30. Depositions by written questions are covered separately.
| Feature | Interrogatories | Oral deposition |
|---|---|---|
| Recipient | Another party | Party or nonparty |
| Answer format | Sworn writing | Sworn oral testimony |
| Follow-up | Further written questions | Live questioning |
| Default count | 25 per other party* | 10 per side* |
| Timing | 30-day response* | Reasonable written notice |
| Duration | No examination session | 1 day, 7 hours* |
| Record | Signed answers | Transcript or recording |
*Each asterisk marks a default that can change. Under Rule 33(a)(1), the 25 includes all discrete subparts and can be changed by stipulation or court order. The ten depositions count Rules 30 and 31 together for each named side (plaintiffs, defendants or third-party defendants), and going beyond ten requires leave unless the parties stipulate (Rule 30(a)(2)(A)(i)). The 30-day response period in Rule 33(b)(2) can be shortened or lengthened by a permitted stipulation or court order. The one-day, seven-hour limit in Rule 30(d)(1) yields to stipulation or order. The court must allow additional time consistent with Rule 26(b)(1) and (2) if needed to examine the deponent fairly or if a person or circumstance impedes or delays the examination.
What interrogatories can establish
Interrogatories go only to another party, which may itself be a witness. A party may serve them on “any other party” under Rule 33(a)(1), and the answers must come in writing and under oath, to the extent a question is not objected to (Rule 33(b)(3)).
Party answers, available information and signatures
An individual answers for themselves. An entity answers through an officer or agent, who must furnish the information available to the party (Rule 33(b)(1)). That is wider than one person’s memory, which is why written answers often draw on records and on input from several people.
The person who answers signs the answers, and an attorney who objects signs the objections (Rule 33(b)(5)). Drafting help does not replace the answerer’s oath.
Facts and contentions
Interrogatories are not limited to background facts. Under Rule 33(a)(2), a question is not objectionable only because it asks for an opinion or contention that relates to fact, or the application of law to fact. The court may defer an answer to a contention question until a later stage, as the rule provides. For sample wording, see our interrogatory questions and answers.
What an oral deposition adds
A party can depose any person, including a party, by oral examination, and ordinarily needs no leave of court to do it (Rule 30(a)(1)). Attendance of a nonparty may be compelled by subpoena under Rule 45, which this article does not cover.
Live follow-up and the testimony record
The main procedural difference is the live exchange. The examiner can ask a follow-up question right after an answer, and the witness answers on the spot. That is an advantage in format, not a guarantee of fuller or more truthful testimony.
The noticing party gives reasonable written notice to every other party, with the time and place and identifying information for the deponent (Rule 30(b)(1)). The notice states how the testimony will be recorded. Unless the court orders otherwise, the recording may be audio, audiovisual or stenographic (Rule 30(b)(3)(A)). So a deposition does not always mean a stenographic transcript.
Remote depositions require a stipulation or a court order on motion (Rule 30(b)(4)).
A deposition by written questions is different
Rule 31 allows a deposition by written questions, which is sometimes mistaken for interrogatories. The party serves its questions on every other party, with notice. An officer then takes the testimony and prepares and certifies the deposition (Rule 31(a)(3) and 31(b)).
Interrogatory answers, by contrast, are prepared and signed by the party itself under Rule 33. Rule 31 also lacks the spontaneous follow-up of an oral deposition, because further questions are served in set rounds (Rule 31(a)(5)).
Federal limits, timing and objections
The 25-question and 30-day interrogatory defaults
A party may serve no more than 25 written interrogatories, including all discrete subparts, on any other party unless the parties stipulate or the court orders otherwise. A court may grant leave for more, consistent with Rule 26(b)(1) and (2) (Rule 33(a)(1)). The limit is not 25 per case or 25 per set.
Answers and objections are due within 30 days after service, unless a Rule 29 stipulation or a court order sets another time (Rule 33(b)(2)). Objections must be stated with specificity. A ground not stated in a timely objection is waived unless the court excuses the failure for good cause (Rule 33(b)(4)).
The deposition count and seven-hour default
Leave is needed, absent a stipulation, if a deposition would result in more than ten taken under Rules 30 and 31 by the plaintiffs, the defendants or the third-party defendants. Ten is not a limit per lawyer or per witness.
The separate duration default is one day of seven hours unless stipulated or ordered otherwise. Additional time must be allowed consistent with Rule 26(b)(1) and (2) when needed for fair examination or when the examination is impeded or delayed (Rule 30(d)(1)).
Absent a stipulation, leave is also needed to depose someone already deposed in the case or to take a deposition before the Rule 26(d) timing. For an early oral deposition, the exception requires certification in the notice, with supporting facts, that the deponent is expected to leave the United States and be unavailable for examination in this country after that time (Rule 30(a)(2)(A)(ii)–(iii)). A deponent confined in prison also requires leave, and the court must grant it to the extent consistent with Rule 26(b)(1) and (2) (Rule 30(a)(2)(B)).
Scope applies to both, but objections work differently
Both tools reach nonprivileged matter relevant to a claim or defense and proportional to the needs of the case. Information need not be admissible to be discoverable (Rule 26(b)(1)). The court must limit the frequency or extent of discovery if it determines that the discovery is unreasonably cumulative or duplicative, can be obtained from a more convenient, less burdensome or less expensive source, or falls outside Rule 26(b)(1)’s scope. It must also limit discovery if the requesting party has had ample opportunity to obtain the information through discovery in the action (Rule 26(b)(2)(C)).
In written answers, the responding party states its objections and answers the rest (Rule 33(b)(3)–(4)). At an oral deposition, objections are noted on the record, but the examination generally proceeds subject to them. Objections must be concise, nonargumentative and nonsuggestive, and a lawyer may instruct a deponent not to answer only to preserve a privilege, enforce a court-ordered limitation or present a motion under Rule 30(d)(3) (Rule 30(c)(2)). For more on objections, see our discovery objections reference.
How plaintiff firms can use both tools
The following example is invented to illustrate a discovery workflow. It is not advice for any particular case.
An employee challenges a performance-based termination. The employee’s team needs to know who made the decision and why.
Identify the decision and the people involved
The team serves an interrogatory on the employer asking it to identify the people who took part in the termination decision and to state the facts it relies on. To the extent the question is not objected to, the employer answers through an officer or agent using the information available to it; the answer must be under oath and signed (Rule 33(b)(1), (3), (5)).
The question seeks facts and contentions permitted by Rule 33(a)(2), subject to Rule 26(b)(1)’s relevance, privilege and proportionality limits. The written answer gives names and a stated factual basis.
Use testimony to clarify what remains unresolved
Suppose the answer names a manager and refers to a meeting. The team can then notice the manager’s oral deposition to ask what was said at the meeting and what a document reference means. The live format allows follow-up questions that a written answer cannot. Nothing about the format guarantees an admission.
Reconcile new information and plan the work
The attorney compares the written answers with what later testimony and documents show. Under Rule 26(e)(1)(A)–(B), a party that has answered an interrogatory must supplement or correct the answer in a timely manner if it learns the answer is materially incomplete or incorrect, unless the corrective information has otherwise been made known to the other parties in discovery or in writing. The party must also supplement or correct as ordered by the court.
Written-first is a workflow choice, not a required order. Under Rule 26(d)(3), methods of discovery may be used in any sequence unless the parties stipulate or the court orders otherwise, and one party’s discovery does not require another to delay.
Cost drivers differ by tool. Interrogatories mean drafting, collecting information from the client and reviewing answers. Depositions mean scheduling, examination and recording, and the noticing party bears the recording costs (Rule 30(b)(3)(A)). The rules do not rank one tool as cheaper overall. For the response side, see our federal discovery response workflow.
How answers and testimony may be used in court
Interrogatory answers are subject to evidence rules
Interrogatory answers may be used to the extent allowed by the Federal Rules of Evidence (Rule 33(c)). That is a qualified permission, not a rule that answers bind a party conclusively. Interrogatory answers are also not the same as admissions under Rule 36(b).
Deposition use depends on Rule 32
At a hearing or trial, a deposition may be used against a party if the party was present or represented at the deposition or had reasonable notice of it. The use must also be admissible under the rules of evidence as though the witness were present, and it must fall within a permitted use in Rule 32(a)(2)–(8) (Rule 32(a)(1)).
Permitted uses include:
- Contradicting or impeaching the deponent’s testimony as a witness (Rule 32(a)(2)).
- Use by an adverse party, for any purpose, of the deposition of a party or of someone who, when deposed, was the party’s officer, director, managing agent or designee under Rule 30(b)(6) or 31(a)(4) (Rule 32(a)(3)).
- Use of a witness’s deposition where the court finds the witness unavailable on grounds listed in the rule, such as death or inability to attend because of illness (Rule 32(a)(4)).
A deposition therefore does not replace live testimony in every case.
State rules
This comparison covers federal civil discovery. For a separate state-court guide, see responding to interrogatories in California.
Draft interrogatory responses with Briefpoint
Briefpoint supports the written side of this comparison. It drafts interrogatory responses and objections for attorney review, and the output is editable in Microsoft Word. The attorney keeps final review and the decision on every answer.
Client Bridge sends plain-language questions to the client by secure link, so the client can answer and upload documents for the attorney to review. A client’s submission provides information for attorney review; it does not replace the formal response. Under Rule 33(b)(2)–(5), answers must be given under oath to the extent not objected to and signed by the answerer; an attorney who objects signs the objections. The responding party must also serve its answers and objections.
The Briefpoint features discussed here support written discovery: drafting responses and objections, and collecting client information for attorney review. See how they fit plaintiff-side practices.
Book a demo to see how Briefpoint supports your interrogatory response workflow.
Watch the Briefpoint demo:
FAQs About Interrogatories vs Deposition
Are interrogatories or depositions better in a civil case?
Neither is better in every case. Interrogatories gather a party’s information and contentions in writing, while an oral deposition allows live questioning under oath or affirmation (Rule 30(c)(1)). Both operate within the scope of Rule 26(b)(1). Which one supplies what a case needs depends on who holds the information and on the limits that apply.
Do interrogatories have to come before a deposition?
No. Under Rule 26(d)(3), methods of discovery may be used in any sequence unless the parties stipulate or the court orders otherwise. Discovery generally cannot begin before the Rule 26(f) conference, subject to the exceptions in Rule 26(d)(1). Serving interrogatories first is one workflow, and nothing in the rule requires it.
Is a deposition by written questions the same as interrogatories?
No. Under Rule 31, written questions are served on the parties, and an officer takes and certifies the testimony. Under Rule 33(b)(3), interrogatory answers are prepared by the party and given in writing under oath. The first is a deposition taken through an officer, and the second is a party’s own written response.
How many interrogatories and depositions are allowed in federal court?
A party may serve up to 25 interrogatories, including discrete subparts, on any other party unless stipulated or ordered otherwise (Rule 33(a)(1)). For depositions, leave is required absent stipulation if more than ten would be taken under Rules 30 and 31 by the plaintiffs, the defendants or the third-party defendants (Rule 30(a)(2)(A)(i)). Neither number is per case.
Can interrogatory answers and deposition testimony be used at trial?
Possibly, but admissibility is not guaranteed. Interrogatory answers may be used to the extent the Federal Rules of Evidence allow (Rule 33(c)). A deposition may be used against a party who was present or represented at the deposition or had reasonable notice, if the evidence rules are satisfied and a permitted use applies, such as impeachment (Rule 32(a)(1)–(3)).
The information provided on this website does not, and is not intended to, constitute legal advice; instead, all information, content, and materials available on this site are for general informational purposes only. Information on this website may not constitute the most up-to-date legal or other information. This website contains links to other third-party websites. Such links are only for the convenience of the reader, user or browser. Readers of this website should contact their attorney to obtain advice with respect to any particular legal matter. No reader, user, or browser of this site should act or refrain from acting on the basis of information on this site without first seeking legal advice from counsel in the relevant jurisdiction. Only your individual attorney can provide assurances that the information contained herein – and your interpretation of it – is applicable or appropriate to your particular situation. Use of, and access to, this website or any of the links or resources contained within the site do not create an attorney-client relationship between the reader, user, or browser and website authors, contributors, contributing law firms, or committee members and their respective employers.
READ MORE