Ezel / Ethics Opinions / ABA
ABA 2005-10-01

What must a lawyer do after receiving a document the other side sent by mistake?

Short answer: Just notify the sender. The opinion concludes that under amended Rule 4.4(b) a lawyer who receives an inadvertently sent document need only promptly notify the sender, and need not refrain from reading it or follow the sender's instructions; it withdraws Formal Opinion 92-368.
Currency note: this opinion is from 2005
Subsequent statutory amendments, court decisions, or later opinions or rule amendments may have changed the analysis. Treat this page as historical context, not current legal advice. Verify current law before relying on any specific rule, deadline, or remedy mentioned here.
Disclaimer: Advisory only. Not binding precedent.
About this page: The plain-English summary, reader guidance, and Q&A below were written by Ezel based on the official ethics opinion. The original opinion (linked at the bottom of this page, or PDF in the sidebar) is the authoritative source for any reliance.
View original ethics opinion (PDF)

ABA Formal Opinion 05-437: Inadvertently Sent Documents

Short answer: The opinion concludes that a lawyer who receives a document from opposing parties or their counsel and knows or reasonably should know it was inadvertently sent must only promptly notify the sender so the sender can take protective measures; to the extent Formal Opinion 92-368 imposed further obligations, it is withdrawn.

Disclaimer: This is an advisory ethics opinion. Advisory opinions are not binding; they interpret the American Bar Association's Model Rules of Professional Conduct and are persuasive authority. This summary is for research purposes only and is not legal advice. Verify current rules before acting on any specific guidance.

About this page: The plain-English summary and Q&A below were written by Ezel based on the official opinion. We do not reproduce the opinion text on this page; follow the linked source for the official text, which controls.

Plain-English summary

The opinion revisits Formal Opinion 92-368, which in 1992 had imposed three obligations on a lawyer who received inadvertently sent confidential materials: refrain from examining them, notify the sending lawyer, and abide by the sending lawyer's instructions. The committee reconsiders that guidance in light of the February 2002 amendments to the Model Rules, which added Rule 4.4(b) to address the precise situation.

The committee explains that the amendment "not only directly addressed the precise issue discussed in Formal Opinion 92-368, but narrowed the obligations of the receiving lawyer." Rule 4.4(b) obligates the receiving lawyer only to promptly notify the sender of the inadvertent transmission. It does not require the lawyer to refrain from examining the materials or to abide by the sender's instructions. The committee points to Comment [2], which says whether additional steps, such as returning the original, are required is a matter of law beyond the scope of the Rules, as is whether the privilege has been waived. Comment [3] adds that where applicable law does not require return, the decision to voluntarily return a document is a matter of professional judgment ordinarily reserved to the lawyer.

Because the conclusion of Formal Opinion 92-368 now conflicts with amended Rule 4.4, the committee withdraws it. The result is a narrow, bright-line ethical duty: prompt notice to the sender, with everything beyond that governed by other law and professional judgment rather than the Rules.

In practice

Under this opinion, a lawyer who realizes a received document was sent by mistake satisfies the Model Rules by promptly telling the sender; the Rules do not require the lawyer to stop reading or to send the document back. The opinion locates questions of waiver and return outside the ethics rules, in substantive law and professional judgment. Because states adopted Rule 4.4(b) on varying timelines and some impose additional duties, the page reflects the committee's reading of the amended Model Rule rather than the rule in any particular jurisdiction.

Common questions

Q: Opposing counsel emailed me a privileged memo by accident. Do I have to stop reading it?

A: Not under the Model Rules. The opinion states that Rule 4.4(b) "does not require the receiving lawyer either to refrain from examining the materials or to abide by the instructions of the sending lawyer." The duty is to "promptly notify the sender."

Q: Do I have to return the document?

A: Not as a matter of the Rules. The committee explains that the decision to voluntarily return "is a matter of professional judgment ordinarily reserved to the lawyer," and whether return is required is a question of law.

Q: Is the old ABA opinion still good?

A: No. The committee concluded that "because the conclusion of Formal Opinion 92-368 presently conflicts with amended Rule 4.4, the opinion is hereby withdrawn."

Background and rules framework

The opinion interprets Model Rule 4.4(b) (the duty to promptly notify the sender of an inadvertently sent document) and its Comments [2] and [3], and references Rules 1.2 and 1.4 on the allocation of decision-making between lawyer and client. It is the companion to Formal Opinion 06-440, which applied the same reasoning to materials disclosed through a third party's unauthorized act.

Citations and references

Rules of Professional Conduct:

  • ABA Model Rule 4.4(b) and Comments [2], [3] (inadvertently sent documents)
  • ABA Model Rules 1.2, 1.4 (allocation of authority; communication)

Other opinions cited:

  • ABA Formal Op. 92-368 (1992): withdrawn by this opinion

See also

Source