What is a without prejudice offer and can it be used against me?

A without prejudice communication is a genuine attempt to settle a dispute, and the rule protects it from being used as evidence in the proceeding to prove admissions or the merits. That means the court will normally not be told of the offer while it decides the case. A different kind of offer, sometimes called a Calderbank offer, is made without prejudice save as to costs, and can be shown to the judge after judgment on the merits to influence a costs order, for example if the other party rejected a fair offer and did not do better at trial. In High Court proceedings, formal settlement offers under the High Court Rules can also affect costs. Label communications carefully and get legal advice before making one.