Res inter alios acta meaning

A Latin maxim meaning “a thing done between others”. In practice it denotes the general rule that dealings, statements or events involving third parties are normally irrelevant to, and should not prejudice, the rights and liabilities in dispute between the parties before the court. It is not defined by statute; it is a descriptive common-law expression recognised in case law and used across England & Wales, Scotland, Northern Ireland and Ireland with broadly consistent effect. Typical applications include: - Evidence: third‑party transactions or conduct are usually inadmissible unless they are directly relevant to a fact in issue (for example, agency, knowledge/notice, conspiracy or estoppel), or fall within established evidential gateways. - Damages: collateral benefits from third parties (such as certain insurance, gifts or benevolence) and settlements with others are commonly treated as res inter alios acta and not deducted when assessing damages, subject to recognised exceptions. - Contract/privity: a contract or act between others generally cannot impose obligations on, or be used to the detriment of, a non-party. The maxim operates alongside modern rules of relevance, hearsay and statutory regimes; it does not bar third‑party material where the law makes it probative and admissible.