The New York bill of particulars: thirty days, and objecting to one item doesn't buy time on the rest
New York procedure · Last verified August 17, 2026
The bill of particulars is not discovery, though it sits in the discovery article and behaves a little like an interrogatory. It is an amplification of a pleading: a demand that the other side say precisely what its claim consists of.
New York uses it heavily, particularly in personal injury cases, and the rule contains one trap that costs defendants and plaintiffs alike.
What it is
CPLR 3041 is a single sentence:
Any party may require any other party to give a bill of particulars of such party's claim, or a copy of the items of the account alleged in a pleading. As used elsewhere in this article, the term "bill of particulars" shall include "copy of the items of an account."
Note "any party … any other party." This is not a plaintiff-only or defendant-only device. A plaintiff can demand particulars of an affirmative defence or a counterclaim.
Thirty days — and the trap
CPLR 3042(a):
Demand. A demand for a bill of particulars shall be made by serving a written demand stating the items concerning which particulars are desired. Within thirty days of service of a demand for a bill of particulars, the party on whom the demand is made shall serve a bill of particulars complying with each item of the demand, except any item to which the party objects, in which event the reasons for the objection shall be stated with reasonable particularity. The assertion of an objection to one or more of the items in the demand shall not relieve the party on whom the demand is made from the obligation to respond in full within thirty days of service of the demand to the items of the demand to which no objection has been made.
That last sentence is the whole point, and it exists because people used to do exactly the opposite. Serving a set of objections is not a response. The unobjected-to items still have to be answered in full, within the same thirty days.
So a timely response to a mixed demand has two parts in one document:
- the particulars themselves, for every item you are not objecting to; and
- your objections, with reasons stated with reasonable particularity — not a bare "objected to as improper."
What can be demanded in a personal injury case
CPLR 3043(a) lists nine categories that "may be required" in personal injury actions:
(1) The date and approximate time of day of the occurrence; (2) Its approximate location; (3) General statement of the acts or omissions constituting the negligence claimed; (4) Where notice of a condition is a prerequisite, whether actual or constructive notice is claimed; (5) If actual notice is claimed, a statement of when and to whom it was given; (6) Statement of the injuries and description of those claimed to be permanent … (7) Length of time confined to bed and to house; (8) Length of time incapacitated from employment; and (9) Total amounts claimed as special damages for physicians' services and medical supplies; loss of earnings, with name and address of the employer; hospital expenses; nurses' services.
Item (3) is the one that does the most work — a "general statement of the acts or omissions constituting the negligence claimed" is where a vague complaint gets pinned down. Note the word general: the rule does not demand evidentiary detail.
Items (4) and (5) matter in premises cases, where notice of a condition is an element.
For motor vehicle cases, item (6) also reaches the serious-injury and economic-loss thresholds defined in the Insurance Law.
Amending and supplementing — two different things
CPLR 3042(b) gives one free amendment:
Amendment. In any action or proceeding in a court in which a note of issue is required to be filed, a party may amend the bill of particulars once as of course prior to the filing of a note of issue.
Once, as of right, and only before the note of issue. After that, you need leave.
CPLR 3043(b) is separate, and it survives the note of issue:
Supplemental Bill of Particulars Without Leave. A party may serve a supplemental bill of particulars with respect to claims of continuing special damages and disabilities without leave of court at any time, but not less than thirty days prior to trial. Provided however that no new cause of action may be alleged or new injury claimed and that the other party shall upon seven days notice, be entitled to newly exercise any and all rights of discovery but only with respect to such continuing special damages and disabilities.
The distinction is exact:
| Amendment — CPLR 3042(b) | Supplemental bill — CPLR 3043(b) | |
|---|---|---|
| How often | once as of course | no stated limit |
| Cut-off | before the note of issue | not less than 30 days before trial |
| What it may cover | the bill generally | continuing special damages and disabilities only |
| New causes of action or new injuries | — | prohibited |
| Consequence for the other side | — | reopens discovery on those items, on 7 days' notice |
A "supplemental" bill that alleges a new injury is not a supplemental bill, and serving one reopens discovery against you on the items it covers.
If the other side does not respond
CPLR 3042(c) gives two routes:
Failure to respond or to comply with a demand. If a party fails to respond to a demand in a timely fashion or fails to comply fully with a demand, the party seeking the bill of particulars may move to compel compliance, or, if such failure is willful, for the imposition of penalties pursuant to subdivision (d) of this rule.
And (d) connects the failure to the general discovery-sanctions provision:
Penalties for refusal to comply. If a party served with a demand for a bill of particulars willfully fails to provide particulars which the court finds ought to have been provided pursuant to this rule, the court may make such final or conditional order with regard to the failure or refusal as is just, including such relief as is set forth in section thirty-one hundred twenty-six of this chapter.
CPLR 3126 is the sanctions arsenal — striking pleadings, preclusion, resolving issues against the defaulting party. The gate is wilfulness; an ordinary failure supports a motion to compel, not penalties.
Overbroad demands cut both ways
CPLR 3042(e) is the answer to a demand that asks for everything:
Service of improper or unduly burdensome demands. If the court concludes that the demand for particulars, or a part thereof, is improper or unduly burdensome, in addition to vacating or modifying the demand, the court may make such order with regard to the improper or unduly burdensome demand as is just.
So a party who serves a boilerplate demand covering every conceivable item is exposed to an order under (e), not merely to having the demand trimmed.
How New York compares
| New York | New Jersey | Federal | |
|---|---|---|---|
| Device exists | yes — bill of particulars | no | abolished |
| Amplifies | the pleading | — | — |
| Time to respond | 30 days | — | — |
| Objection excuses the rest | no — expressly | — | — |
| Free amendment | once, before the note of issue | — | — |
| Supplement after the note of issue | yes, continuing damages only, 30 days before trial | — | — |
A short checklist
- Calendar thirty days from service of the demand.
- Answer everything you are not objecting to, in full, inside those thirty days. Objections do not extend the deadline for the rest.
- State the reasons for each objection with reasonable particularity. A bare objection is not a response.
- If you are demanding in a personal injury case, work from the CPLR 3043(a) list — the nine categories are what the rule contemplates.
- Use your one free amendment before the note of issue is filed. After that you need leave.
- Keep supplemental bills to continuing special damages and disabilities, serve them at least thirty days before trial, and do not allege a new injury or cause of action.
- Expect discovery to reopen on anything a supplemental bill covers, on seven days' notice.
- Move to compel for a late or incomplete response; reserve a CPLR 3126 penalty application for wilful failures.
- Do not serve a boilerplate demand. CPLR 3042(e) lets the court do more than trim it.
Where these rules live
- CPLR 3041 — Bill of particulars in any case
- CPLR 3042 — Procedure for bill of particulars
- CPLR 3043 — Bill of particulars in personal injury actions
- CPLR 3044 — Verification of bill of particulars in personal injury action
- CPLR 3126 — Penalties for refusal to comply with order or to disclose
This page explains what the statute says. It isn't legal advice, and what makes a demand unduly burdensome under CPLR 3042(e) is developed in case law this site doesn't cover.