CPLR 2103 is the New York rule that governs how lawyers and parties exchange papers after a civil lawsuit has already been started. It covers motions, discovery demands, notices, and every other filing that moves between the sides during the case. The rule tells you who can serve the papers, who has to receive them, which delivery methods count, and how many extra days the recipient gets to respond depending on the method used. It does not cover the summons and complaint that begin the case; those follow separate service rules.
Who Can Serve and Who Must Receive
Under CPLR 2103(a), the person making service must be at least eighteen years old and cannot be a party to the lawsuit.1New York State Senate. New York Civil Practice Law and Rules R2103 A plaintiff cannot mail interrogatories to the defendant themselves, and a defendant cannot hand-deliver opposition papers to the plaintiff’s lawyer. The task usually falls to a paralegal, a legal assistant, another staff member, or a professional process server.
Once an attorney has appeared for a party, all further papers go to the attorney, not to the party. Serving the represented party directly can be treated as defective. When one attorney represents several parties, one copy on that attorney is enough. If the party has no lawyer, CPLR 2103(c) directs service on the individual using one of the approved methods described below.1New York State Senate. New York Civil Practice Law and Rules R2103 The same fallback applies if opposing counsel cannot be located or served. A court may also order service on a different person when circumstances call for it.
The Seven Approved Methods of Service
CPLR 2103(b) lists seven ways to get papers to the other side. Each has its own completion rule, and choosing the wrong step can make the service defective.
Personal Delivery to the Attorney
Paragraph (b)(1) allows handing the papers directly to the attorney. That is always valid.1New York State Senate. New York Civil Practice Law and Rules R2103
Delivery at the Attorney’s Office
Under paragraph (b)(3), if you go to the office and the attorney is not there, the rule depends on the office’s status. If the office is open, leave the papers with the person in charge, or in a conspicuous place if no one is in charge. If the office is closed, deposit the papers in the office letter drop or mailbox in a sealed wrapper addressed to the attorney.1New York State Senate. New York Civil Practice Law and Rules R2103
Delivery at the Attorney’s Residence
Paragraph (b)(4) permits leaving papers at the attorney’s home with a person of suitable age and discretion, but only when service at the office cannot be made.1New York State Senate. New York Civil Practice Law and Rules R2103 It is a last-resort method.
Paragraph (b)(2) authorizes first-class mail, postage prepaid, to the address the attorney has designated for service, or to the last known address if none is designated. Service is complete on deposit in a post office or official USPS depository.1New York State Senate. New York Civil Practice Law and Rules R2103 The legal date is the date of mailing, not the date of receipt, and you do not have to prove the papers actually arrived.
Overnight Delivery
Paragraph (b)(6) allows service by any delivery service that regularly accepts items for overnight delivery to any address in New York.2New York State Senate. New York CVP Section 2103 FedEx and UPS are the common choices. Service is complete when the properly addressed package is deposited with the courier before the cutoff time for overnight delivery. Missing that cutoff pushes the service date to the next day.
Facsimile
Paragraph (b)(5) permits fax service only when the receiving attorney has designated a fax number for that purpose. Listing a fax number in the address block on any paper filed or served in the case counts as consent, and the attorney can later withdraw consent by notice. Fax service is a two-step process. You need both a successful transmission signal and a hard copy mailed to the attorney.1New York State Senate. New York Civil Practice Law and Rules R2103 Skip the follow-up mailing and the service is incomplete.
Electronic Service
Paragraph (b)(7) covers electronic service, including through the New York State Courts Electronic Filing system (NYSCEF). Electronic service is available where authorized by the rules of the Chief Administrator of the Courts, and written consent is required unless the rules provide otherwise. Every paper transmitted electronically must include a subject line indicating it relates to a court proceeding.2New York State Senate. New York CVP Section 2103
Where NYSCEF e-filing is mandatory, all parties must file and serve through the system regardless of individual consent.3New York State Unified Court System. NYSCEF – Frequently Asked Questions In consensual e-filing cases, each attorney who wants to participate must separately record consent in NYSCEF for that specific case.4New York State Unified Court System. 22 NYCRR 202.5-b – Electronic Filing in Supreme Court; Consensual Program One party’s refusal to consent does not prevent the other parties from e-filing among themselves.
Extra Response Time Based on the Method Used
Because mail and overnight packages take time to arrive, CPLR 2103 gives the recipient extra days whenever a legally prescribed deadline runs from the date of service. The extensions are automatic. No one has to request them.
- Mail from within New York: five extra days.1New York State Senate. New York Civil Practice Law and Rules R2103
- Mail from outside New York but within the United States: six extra days.1New York State Senate. New York Civil Practice Law and Rules R2103
- Overnight delivery: one extra business day.1New York State Senate. New York Civil Practice Law and Rules R2103
The one-day gap between in-state and out-of-state mail matters. A New York attorney working from a satellite office in New Jersey who mails papers from there gives the opponent six days, not five. Personal delivery, office delivery, and electronic service through NYSCEF carry no automatic extension; the clock runs from the date of service.
How the Extensions Interact With Motion Deadlines
The mailing extension stacks on top of the notice period set by CPLR 2214. A notice of motion and supporting papers must be served at least eight days before the return date, and if the motion demands it and is served at least sixteen days before the return date, answering papers are due at least seven days before that date.5FindLaw. New York Civil Practice Law and Rules CVP Rule 2214
When you mail those papers instead of hand-delivering them, add the CPLR 2103 extension to the CPLR 2214 period. A notice of motion mailed from within New York that ordinarily requires eight days’ notice must be mailed at least thirteen days before the return date (eight plus five). Sent by overnight delivery, the minimum becomes nine days (eight plus one business day). Courts routinely reject late-served papers, so the arithmetic has to be right.
When the Last Day Falls on a Weekend or Holiday
New York General Construction Law section 25-a extends any deadline that lands on a Saturday, Sunday, or public holiday to the next business day.6New York Public Law. New York General Construction Law Section 25-A So if a five-day mailing extension pushes your response deadline to a Sunday, you have until Monday to act.
Proving Service Was Made
CPLR 306 sets the content of proof of service. The proof must identify the papers served, the person who received them, the date and time, the address or place of service, the manner of service, and facts showing the server was authorized to make service.7FindLaw. New York Civil Practice Law and Rules CVP Rule 306
The form depends on who served. A sheriff or other public officer files a certificate. Anyone else files an affidavit sworn under penalty of perjury.7FindLaw. New York Civil Practice Law and Rules CVP Rule 306 For mail service, a USPS certificate of mailing confirms the date the envelope was handed to the Postal Service, though it does not track delivery or capture a recipient signature.8USPS. Certificate of Mailing – The Basics For fax service, keep the transmission confirmation report along with proof that the follow-up hard copy went out.
What Happens When Service Is Defective
The immediate consequence of defective service is that the court can disregard the paper. A motion served without adequate notice can be denied on procedural grounds before the judge reaches the merits. Opposition papers served a day late can be rejected, leaving the motion unopposed. Missed deadlines, denied motions, and forfeited arguments follow from small counting errors.
The stakes are different for the summons and complaint that start a case. Under CPLR 306-b, if initial process is not served within the required time, the court must dismiss the action against that defendant unless the plaintiff shows good cause or the interest of justice warrants an extension.9New York State Senate. New York Civil Practice Law and Rules CVP 306-b That dismissal rule sits outside CPLR 2103, which governs only the papers that follow the pleading.
Filing a false affidavit of service carries its own exposure. Swearing under oath to a mailing date that did not happen is perjury, and courts treat the integrity of proof of service seriously. A pattern of unreliable affidavits can produce sanctions and grievance referrals for the attorneys involved.