Robust witness evidence can help the taxpayer prevail in tax disputes, even where HMRC has identified documentary evidence it believes is decisive. A best practice approach to resolving disputes out of court involves establishing and evidencing the full range of facts to the same professional standard as in litigation. The tribunal rules on the use of evidence offer flexibility for litigants in the preparation of a case, and evidence may be admitted which would not be admissible in a civil trial. The articulation of a clear, cogent and credible witness narrative can be a key factor for taxpayer success.