A cross-appeal is an appeal lodged by a respondent who, while already a party to an existing appeal, seeks to challenge a different aspect of the same decision. In practice, it allows the respondent not only to resist the appellant’s appeal but also to seek to vary, reverse or otherwise alter the order under appeal in their own favour.Across England and Wales, Scotland, Northern Ireland and Ireland, the concept is broadly consistent, though governed by distinct appellate rules and court procedures (for example, the Civil Procedure Rules in England and Wales, and equivalent court rules in the other jurisdictions). Time limits and formal requirements for filing a cross-appeal typically differ from those for a simple respondent’s notice or answers.A cross-appeal is commonly used where the respondent accepts that the decision cannot stand as made, or wishes to protect an alternative route to success if the main appeal succeeds. It has important tactical implications: failing to cross-appeal may preclude the respondent from seeking more favourable relief or from challenging adverse findings that underpin the order.