Res judicata
Disputes & Litigation

Res judicata refers to a decision in English law which has been decided once and for all by a judicial tribunal, such that the decision may only be challenged on appeal by another judicial tribunal higher in the judicial hierarchy. For example, a decision made at first instance by a High Court judge at a hearing may only be challenged by appealing to the Court of Appeal, and then to the House of Lords. Other than this procedure through the court hierarchy, the subject matter of the decision may not be relitigated by the parties at a later date.

The principle prevents the same claim from being raised again between the parties to the litigation (for example, the claimant raising the same claim for recovery or damages or other relief) or calling into question the correctness of the earlier decision (for example, where the defendant argues that a damages award is excessive). The principle applies to matters of fact and law, mixed questions of fact and law. When a judgment is entered in respect to the facts, the cause of action and legal rights of the parties are extinguished and said to 'merge in the judgment'. The correctness of the decision is irrelevant, other than on appeal. A final decision must be appealed in order to be set aside the judgment or have it varied.

As such, it operates as an estoppel to further litigation and extinguishes the legal rights that gave rise to the litigation in the first place.

Thus, the key features of this form of estoppel are that:

1. it prevents a party from denying in later litigation the correctness of the decision in the previous litigation; and
2. the cause of action merges in a judgment in favour of the claimant.

Res judicata should be distinguished from estoppel by record. When a matter is caught by the doctrine, it is the res judicata that estops further litigation, and not the fact that a record was made of the decision.

Making out the Defence

The party seeking to rely on it in subsequent litigation must show that the previous decision was:

1. a judicial decision;
2. made by a tribunal having jurisdiction over the parties;
3. final;
4. made on the merits of the case; and
5. covered the same question as it raises in the later litigation.

Furthermore, the decision parties to the later decision must have been parties to the earlier decision where the decision was made in personam or show that the decision was made in rem. It is the record of the decision that is conclusive of what was adjudicated during the previous litigation.

There are two types, each with the same effect: issue estoppel and action estoppel. Cause of action estoppel prevents a party asserting the existence of a particular cause of action, as the particular cause of action has previously been determined. Issue estoppel applies where some fundamental issue forms part of the issues determined in earlier proceedings.

A decision for the purposes of res judicata may be a decree, order, judgment or sentence. What matters is that the decision is a judicial decision as opposed to an administrative decision.

The Practical Effect

Res judicata is the reason why judicial decisions are different to almost any other type or kind of decision. A judicial decision is final and conclusive of the rights between the parties to litigation – it marks the termination of disputes of the litigation, subject to an appeal. Consequently litigants are not exposed to a multiplicity of proceedings on the same facts.

There are limited exceptions, such as in running down cases, the application to revenue authorities and divorce proceedings, particularly in cases involving misconduct.