Evidence Rules in the U.S. Tax Court

The U.S. Tax Court explicitly applies the Federal Rules of Evidence to all trials.

Under Tax Court Rule 143(a) and Internal Revenue Code § 7453, trials follow the Federal Rules of Evidence, with relevance evaluated under FRE 401–403. Statements outside the trial record, such as briefs or pleadings not admitted into evidence, are excluded.

International tax cases in the Tax Court frequently involve several additional considerations:

Expert Reports (Rule 143(g))

Expert reports are generally required, especially in transfer pricing or valuation disputes. They should detail the expert’s opinions, basis, facts considered, qualifications, prior testimony, and compensation. Noncompliance may lead to exclusion of testimony.

Foreign Law (Rule 146)

When a party relies on foreign law, it must give notice. The Court can consider any relevant source or material, including expert testimony, even if it would not normally be admissible as evidence. The court’s decision on foreign law is treated as a legal ruling.

Foreign-Based Documents (IRC § 982)

If a taxpayer fails to provide foreign-based records requested by the IRS, the court may bar their later use in the case.

Tax Court cases rely heavily on stipulations of fact, with more limited discovery than other forums. Foreign evidence is often obtained via tax treaties, Tax Information Exchange Agreements (TIEAs), or court orders under IRC § 7456.