Can lawyers who are not in the same firm share office space, and what do they have to do to protect client confidences and avoid conflicts?
ABA Formal Opinion 507: Office Sharing Arrangements With Other Lawyers
Short answer: The opinion concludes that lawyers who are not in the same firm may generally share office space under the Model Rules, provided they take appropriate measures to protect client confidences, avoid misleading the public or clients into thinking they are one firm, supervise shared nonlawyer staff, and run conflict checks; because office-sharing lawyers are not automatically treated as a single firm, they may even represent clients with adverse interests where confidences are shielded and informed consent is obtained.
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 addresses whether and how lawyers who do not practice together may share office space, covering confidentiality, public communications about their relationship, conflicts of interest, and supervision of nonlawyers. Its baseline conclusion is that "it is generally permissible for lawyers to participate in office sharing arrangements with other lawyers under the ABA Model Rules of Professional Conduct," subject to safeguards whose extent "will necessarily depend on the circumstances of each arrangement."
On confidentiality, the opinion explains that "the mere sharing of office space does not automatically equate with the disclosure of client information," but the physical setup must not expose client information to the other lawyers or their staff, and lawyers must avoid discussing matters in common areas. Depending on the circumstances, additional safeguards may be needed, such as separate or secured files, privacy measures, and training, and shared support staff raise the confidentiality stakes and must be supervised under Rule 5.3.
On public communications, the opinion stresses that office-sharing lawyers "must take appropriate steps to clearly communicate the nature of their relationship to the public and to their clients" so as not to imply they are one firm. It points to separate business cards, letterhead, listings, signage, and advertising, and to answering a shared phone with a generic salutation. Where separate signage is impossible, as in some subleased or coworking spaces, the lawyers must still take reasonable measures to prevent client confusion.
On conflicts, the opinion explains that "under the Model Rules, office sharing lawyers are not automatically treated as a single law firm for conflicts of interest purposes." Whether their conflicts are imputed under Rule 1.10(a) depends on a facts-and-circumstances determination of whether they are, or appear to be, associated in a firm. Where they properly shield confidences and do not hold out as one firm, they may represent clients with adverse interests, though Rules 1.4 and 1.7 may require disclosing the arrangement and obtaining each client's informed consent confirmed in writing, and shared staff must not have access to both adverse clients' information. The opinion adds that "merely engaging in informal consultations from time to time does not result in the lawyers being 'associated in a firm' under Model Rule 1.10(a)," but cautions that a consulted lawyer who receives confidential information can pick up a conflict under Rule 1.7(a)(2), paralleling the prospective-client duties of Rule 1.18, so a conflict check before consulting is prudent.
In practice
Under this opinion, lawyers may share office space if they protect client information in the physical and electronic setup, supervise any shared nonlawyer staff under Rule 5.3, and clearly signal to the public and clients that they are separate practices rather than one firm. The opinion holds that office-sharing lawyers are not automatically a single firm for imputation, so where they shield confidences and do not hold out as a firm, they may represent adverse clients with the disclosures and informed written consent that Rules 1.4 and 1.7 require. For consultations between office-sharing lawyers, the opinion notes that occasional informal consultation does not make them a firm, but that running a conflict check first guards against picking up a disqualifying duty.
Common questions
Q: Can lawyers who are not partners share an office suite?
A: Yes. The opinion concludes office sharing is generally permissible under the Model Rules, subject to safeguards for confidentiality, conflicts, supervision of shared staff, and clear communication about the relationship.
Q: Are office-sharing lawyers treated as one firm for conflicts?
A: Not automatically. The opinion says imputation under Rule 1.10(a) depends on whether they are or appear to be associated in a firm, judged on the facts, so office sharing alone does not impute one lawyer's conflicts to another.
Q: Can office-sharing lawyers be on opposite sides of a matter?
A: Per the opinion, yes, where they properly shield client confidences and do not hold themselves out as one firm, but Rules 1.4 and 1.7 may require disclosing the arrangement and getting each client's informed consent confirmed in writing, and shared staff cannot access both clients' information.
Q: What do office-sharing lawyers have to do so clients are not confused?
A: The opinion points to separate business cards, letterhead, listings, signage, and advertising, and answering a shared phone generically; where separate signage is not possible, the lawyers must still take reasonable steps to avoid client confusion about associations.
Background and rules framework
The opinion interprets several Model Rules in the office-sharing context: Rule 1.6 (confidentiality, including the Comment [4] allowance for hypotheticals), Rule 1.7 (conflicts of current clients, including 1.7(a)(2) material limitation), Rule 1.10 (imputation among lawyers "associated in a firm"), Rule 1.18 (prospective clients), Rule 7.1 (false or misleading communications about a lawyer's services, including Comment [7]), Rules 5.1 and 5.3 (supervisory responsibilities), and Rule 1.0(c) (definition of firm). It draws on Formal Opinions 88-356, 98-411, 492, and 498, and on Informal Opinions 1474 and 1486.
Citations and references
Rules of Professional Conduct:
- ABA Model Rule 1.6 (confidentiality), 1.7 (current-client conflicts)
- ABA Model Rule 1.10 (imputation), 1.18 (prospective clients), 1.0(c) (firm)
- ABA Model Rule 7.1 (communications about services), 1.4 (communication)
- ABA Model Rule 5.1, 5.2, 5.3 (supervisory responsibilities)
Other opinions cited:
- ABA Formal Op. 88-356 (1988): when a lawyer is "associated in a firm"
- ABA Formal Op. 98-411 (1998): lawyer-to-lawyer consultations and resulting conflicts
- ABA Formal Op. 492 (2020) and 498 (2021): prospective clients; virtual practice
- ABA Informal Ops. 1474 (1982) and 1486 (1982): shared-space lawyers and adverse interests
See also
- ABA Formal Op. 511R: Confidentiality on Listservs
- ABA Formal Op. 510: Prospective-Client Conflicts
- ABA Formal Op. 513: Duty to Inquire Into Each Representation
Source
- Landing page: ABA Formal Ethics Opinions index
- Original PDF: aba-formal-opinion-507.pdf