§ 312-a.Personal service by mail.
Article 3. Jurisdiction and Service, Appearance and Choice of Court · Last amended 2009 · Last verified July 21, 2026
Full Text of CPLR 312-a
Plain-English Summary
CPLR 312-a gives plaintiffs a cheaper alternative to personal delivery: mailing the summons and complaint (or notice of petition and petition) by first-class mail, along with two copies of a statement of service and an acknowledgment-of-receipt form, plus a prepaid return envelope. It stands alongside, not in place of, the personal-service methods in sections 307, 308, 310, 311, and 312.
Mail service under this section only works if the defendant cooperates. The defendant, an authorized employee, or the defendant's attorney must sign the acknowledgment and mail or deliver it back within thirty days of receiving it. Service is complete on the date that signed acknowledgment goes back to the sender -- not on the date the plaintiff mailed the papers. The acknowledgment, sworn under penalty of perjury, carries the same weight as an affidavit of service and stands as proof of service.
When a complaint or petition rides along with the summons, the defendant's clock to answer runs twenty days from the date the signed acknowledgment is mailed or delivered back, not twenty days from mailing. If the acknowledgment never comes back within thirty days, the plaintiff has to fall back on another method of service, such as personal delivery or substitute service. The court can then tax the added cost of that second attempt against the defendant as a disbursement.
Frequently Asked Questions
Is service by mail under CPLR 312-a complete as soon as I mail the papers?
No. Service is complete only when the defendant signs the acknowledgment of receipt and mails or delivers it back to the sender, not on the date the plaintiff put the papers in the mail.
What happens if the defendant never returns the signed acknowledgment?
The plaintiff must serve the defendant by another method the law allows, such as personal delivery. The court can then charge the defendant, as a disbursement, for the added expense of that second service.
How long does a defendant have to answer after being served by mail?
Twenty days from the date the signed acknowledgment of receipt is mailed or delivered back to the sender, when a complaint or petition was served along with the summons.
Can a corporation be served under CPLR 312-a?
Yes. An authorized employee of the entity, or its attorney or the attorney's employee, may sign the acknowledgment on the entity's behalf.
Is service by mail mandatory, or can a plaintiff choose personal delivery instead?
It's an alternative. CPLR 312-a lets a plaintiff choose mail service instead of the personal-service methods in sections 307, 308, 310, 311, or 312.
Why does the acknowledgment form ask about military service?
The person signing must state whether they're in military service, information relevant to protections under servicemember relief laws before a default judgment can be entered.
Amendment History
Add, L 1989, ch 274, § 2; amd, L 1992, ch 216 § 8; L 1993, ch 459, § 1, eff Jan 1, 1994; L 1996, ch 368, § 1, eff July 30, 1996; L 2009, ch 222, § 1, eff July 14, 2009.