37 CFR § 11.307 - Practitioner as witness.

---
identifier: "/us/cfr/t37/s11.307"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "37 CFR § 11.307 - Practitioner as witness."
title_number: 37
title_name: "Patents, Trademarks, and Copyrights"
section_number: "11.307"
section_name: "Practitioner as witness."
chapter_name: "UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE"
subchapter_number: "A"
subchapter_name: "GENERAL"
part_number: "11"
part_name: "REPRESENTATION OF OTHERS BEFORE THE UNITED STATES PATENT AND TRADEMARK OFFICE"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
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."
regulatory_source: "69 FR 35452, June 24, 2004, unless otherwise noted."
cfr_part: "11"
---


# 11.307 Practitioner as witness.

(a) A practitioner shall not act as advocate at a proceeding before a tribunal in which the practitioner is likely to be a necessary witness unless:

(1) The testimony relates to an uncontested issue;

(2) The testimony relates to the nature and value of legal services rendered in the case; or

(3) Disqualification of the practitioner would work substantial hardship on the client.

(b) A practitioner may act as advocate in a proceeding before a tribunal in which another practitioner in the practitioner's firm is likely to be called as a witness unless precluded from doing so by §§ 11.107 or 11.109.