CPLR 2309 Certificate of Conformity: First Department Excuses the Defect Again

Key Takeaways

• In Donsimoni v Fall, the First Department held that an affidavit acknowledged by a U.S. vice-consul in Paris but lacking a CPLR 2309 certificate of conformity was a mere irregularity.
• The defect “could be corrected nunc pro tunc, if necessary” — it did not require rejecting the affidavit of merit outright.
• The ruling continues the First Department’s liberal, substance-over-form approach to out-of-state and foreign oath defects.
• Since January 1, 2024, amended CPLR 2106 lets any person affirm under penalty of perjury, mooting the certificate-of-conformity problem for most new filings.

Certificate of Conformity Requirements: Another Lenient Ruling

New York’s CPLR 2309 requires foreign documents to be accompanied by a certificate of conformity to be admissible in court proceedings. This technical requirement has been the subject of numerous appellate decisions, with courts taking varying approaches to enforcement. The First Department’s treatment of these procedural requirements has been particularly inconsistent over the years, sometimes strictly enforcing the rule while other times allowing substantial flexibility.

The Donsimoni v Fall decision exemplifies the court’s continued willingness to excuse technical deficiencies in foreign document authentication. This case involved an affidavit of merit from a foreign expert that was properly notarized by U.S. Embassy officials but lacked the required certificate of conformity under CPLR 2309.

Jason Tenenbaum’s Analysis:

Donsimoni v Fall, 2017 NY Slip Op 07092 (1st Dept. 2017)

“The fact that plaintiff’s lone affidavit of merit in opposition to defendant’s summary judgment was acknowledged by a vice-consul in the U.S. Embassy in Paris, France, yet was submitted without a requisite certificate of conformity (see CPLR 2309; Real Property Law § 301, et seq.), constituted an irregularity that could be corrected nunc pro tunc, if necessary (see DaSilva v KS Realty, L.P., 138 AD3d 619 ; Gyamfi v Citywide Mobile Response Corp., 146 AD3d 612 )….”

It is amazing that the Court actually countenanced the certificate of conformity argument in the first place.

The Legal Framework: What CPLR 2309(c) Actually Requires

CPLR 2309(c) provides that an oath taken outside New York must be accompanied by a certificate establishing that it was administered in the manner prescribed by the law of the place where it was taken — the certificate of conformity — with the Real Property Law’s acknowledgment provisions supplying the mechanics. The idea is straightforward: a New York court accepting a Paris or Phoenix affidavit wants some assurance the oath was valid where given.

In practice, the certificate is boilerplate — typically a one-page attorney certification — and that is precisely why courts have grown impatient with motions that try to convert its absence into a dispositive evidentiary objection. The modern trend, exemplified by the DaSilva and Gyamfi citations in Donsimoni, treats the missing certificate as a correctable irregularity rather than a fatal defect, at least absent any showing of prejudice or any genuine doubt that the oath was properly administered.

Donsimoni presented a particularly sympathetic record for leniency: the affidavit of merit was acknowledged by a vice-consul at the U.S. Embassy in Paris — a United States officer expressly in the oath-administration business. Rejecting that document over a missing conformity certificate would have elevated form over substance in the starkest way, which likely explains the author’s reaction that the court “countenanced the argument in the first place.”

Why This Matters in Motion Practice

The certificate-of-conformity objection shows up most often in summary judgment battles, where one side’s critical proof — an expert affidavit of merit, a carrier’s out-of-state claims affidavit, a mailing affidavit from a national vendor — was executed outside New York. In no-fault litigation especially, where insurers’ affiants routinely sit in out-of-state claim centers, the objection was for years a staple of plaintiffs’ opposition papers.

Donsimoni and its companions defang the objection in the First Department: courts will permit the certificate to be supplied nunc pro tunc — retroactively, as if filed on time — rather than strike the affidavit. A litigant banking on a 2309(c) technicality to defeat otherwise competent proof should expect disappointment, though the departments have not always marched in step, and careless papers still hand opponents free arguments.

The 2024 Postscript: CPLR 2106 Largely Moots the Issue

The legislature ultimately did what the case law was inching toward. Effective January 1, 2024, CPLR 2106 was amended to permit any person to submit an affirmation under penalty of perjury in lieu of a notarized affidavit in New York civil practice. An affirmation requires no notary, no jurat, and no certificate of conformity — wherever in the world the affirmant signs it.

For new filings, the out-of-state oath problem that generated this entire body of law is therefore mostly obsolete. But the Donsimoni line remains relevant for affidavits already in litigation files, for documents that other statutes require to be acknowledged or notarized, and for any practitioner who still chooses the affidavit format for an out-of-state witness.

Practice Pointers

• If an opponent raises a missing certificate of conformity, offer to supply it nunc pro tunc; in the First Department, that ends the issue.
• If you are the objector, pair the 2309(c) argument with a substantive attack on the affidavit — standing alone, the technical objection rarely wins.
• Going forward, use an amended CPLR 2106 affirmation for any out-of-state or foreign witness and avoid the notarization framework entirely.
• Do not confuse leniency with license: a defective oath plus prejudice, or an affidavit whose validity is genuinely in doubt, can still be rejected.

Frequently Asked Questions

What is a certificate of conformity under CPLR 2309?

It is a certificate accompanying an oath taken outside New York, establishing that the oath was administered in the manner prescribed by the law of the jurisdiction where it was taken. It is typically a short attorney certification appended to an out-of-state or foreign affidavit.

Is a missing certificate of conformity fatal to an affidavit in New York?

Generally not. In Donsimoni v Fall, the First Department held the omission was an irregularity that “could be corrected nunc pro tunc, if necessary” — consistent with its decisions in DaSilva and Gyamfi treating the defect as curable rather than dispositive.

Do I still need a certificate of conformity after the 2024 CPLR 2106 amendment?

Usually no. Since January 1, 2024, any person may submit an affirmation under penalty of perjury instead of a notarized affidavit, which eliminates the need for a notary and a conformity certificate. The certificate remains relevant only where a notarized affidavit or acknowledged instrument is still used or required.

Related Resources

• IME no-show: it was not mailed — the firm’s cluster hub on mailing and proof-of-service affidavits
• The firm’s Legal Encyclopedia
• No-Fault Defense practice
• 2309 issue
• 2309(c) defect waived (again)
• CPLR 2309 and the ability to submit new evidence in a reply