---
kind: "section"
citation: "37 C.F.R. § 11.109"
title: "37"
number: "11.109"
heading: "Duties to former clients."
url: "https://uscodex.org/cfr/37/11.109"
---

# §11.109. Duties to former clients.

- (a) A practitioner who has formerly represented a client in a matter shall not thereafter represent another person in the same or a substantially related matter in which that person's interests are materially adverse to the interests of the former client unless the former client gives informed consent, confirmed in writing.
- (b) A practitioner shall not knowingly represent a person in the same or a substantially related matter in which a firm with which the practitioner formerly was associated had previously represented a client:
  - (1) Whose interests are materially adverse to that person; and
  - (2) About whom the practitioner had acquired information protected by §§ [11.106](/cfr/37/11.106.md) and [11.109(c)](#c) that is material to the matter; unless the former client gives informed consent, confirmed in writing.
- (c) A practitioner who has formerly represented a client in a matter or whose present or former firm has formerly represented a client in a matter shall not thereafter:
  - (1) Use information relating to the representation to the disadvantage of the former client except as the USPTO Rules of Professional Conduct would permit or require with respect to a client, or when the information has become generally known; or
  - (2) Reveal information relating to the representation except as the USPTO Rules of Professional Conduct would permit or require with respect to a client.

## Notes

### Source

Source: 78 FR 20201, Apr. 3, 2013, unless otherwise noted.

### Authority

Authority: 5 U.S.C. 500; 15 U.S.C. 1123; 35 U.S.C. 2(b)(2), 32, 41; Sec. 1, Pub. L. 113-227, 128 Stat. 2114.

### Source

Source: 69 FR 35452, June 24, 2004, unless otherwise noted.