26 CFR § 601.507 - Evidence required to substantiate facts alleged by a recognized representative.
---
identifier: "/us/cfr/t26/s601.507"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "26 CFR § 601.507 - Evidence required to substantiate facts alleged by a recognized representative."
title_number: 26
title_name: "Internal Revenue"
section_number: "601.507"
section_name: "Evidence required to substantiate facts alleged by a recognized representative."
chapter_name: "INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY"
subchapter_number: "H"
subchapter_name: "INTERNAL REVENUE PRACTICE"
part_number: "601"
part_name: "STATEMENT OF PROCEDURAL RULES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "5 U.S.C. 301 and 552."
regulatory_source: "32 FR 15990, Nov. 22, 1967, unless otherwise noted."
cfr_part: "601"
---
# 601.507 Evidence required to substantiate facts alleged by a recognized representative.
The Internal Revenue Service may require a recognized representative to submit all evidence, except that of a supplementary or incidental character, over a declaration (signed under penalty of perjury) that the recognized representative prepared such submission and that the facts contained therein are true. In any case in which a recognized representative is unable or unwilling to declare his/her own knowledge that the facts are true and correct, the Internal Revenue Service may require the taxpayer to make such a declaration under penalty of perjury.
[56 FR 24009, May 28, 1991]