Collateral Use Of Documents – What Is It And What You Need To Know When Disclosing Documents

When parties are involved in court proceedings, they are often required to disclose documents that they would normally keep private and confidential. To encourage full and frank disclosure, the law generally protects those documents from being used for any other purpose outside the proceedings in which they were disclosed. This rule is embedded in CPR 31.22 and PD 57AD and is known in civil litigation as the “collateral undertaking”. 

This protection can be significant and what constitutes “use” of a document outside of the immediate proceedings is very broad. For example, the courts have held that documents disclosed in litigation cannot be used to put pressure on or threaten a third party outside the proceedings (see: Grosvenor Chemicals [2017] EWHC 1893 (Ch)). Doing anything other than realising, in the course of review for the purposes of the proceedings in which documents are disclosed, that a document would be relevant to contemplated other proceedings, may constitute