Intervention

June 25, 2024

In principle, the court decision in a case is only effective between the parties, i.e. the plaintiff and the defendant (res judicata). This is different in the case of so-called intervening parties: The intervening party (or intervener) participates in the proceedings of the other parties in their own name and supports one of the parties because they have a legal interest in this party winning. The effect of the intervening party under Section 68 of the German Code of Civil Procedure (ZPO) means that in any subsequent proceedings between the intervening party and the party they are supporting, both are bound by the content of the judgement in the first proceedings.

Legal basis and purpose

Intervention is regulated in sections 68-71 of the Code of Civil Procedure, in particular the requirements and types of intervention, as well as joining and the legal status of the intervening party.

The possibility of intervening is intended to help avoid subsequent court proceedings by extending the effect of the judgement to the intervener. Fewer lawsuits are conducive to economic efficiency and legal certainty.

Different types and legal requirements

There are two types of interventions, each with different requirements and effects - the simple intervention pursuant to sections 66 et seq. ZPO and the (rare) contentious intervention pursuant to section 69 ZPO. The court examines the effectiveness of the intervention ex officio, e.g. that the general personal procedural requirements are also met by the intervener.

Simple intervention pursuant to Section 66 ZPO requires pending proceedings (including interim relief, enforcement or arbitration proceedings) between other parties and a reason for intervention. Other parties means that the intervener may not be the main party or the legal representative of one of the main parties. The intervention of the intervener may only relate to one of the parties and can be withdrawn at any time. The reason for intervention is the intervener's own legal interest in an at least partial victory of the supported main party. This can be assumed if there is a legal relationship between the intervener and the subject matter of the dispute or the supported party that is directly or indirectly influenced by the court's decision. However, the interest does not require that the legal force of the judgement also extends to the intervener. Examples of simple intervening parties are, for example, the assertion by one of the parties that they have a claim against the third party, the accession of the former creditor to the new creditor following an assignment or a recourse claim by the third party or the party against the third party.

Intervening in a dispute in accordance with section 69 of the Code of Civil Procedure initially requires the same requirements as simple intervention and additionally that the legal force also extends to a legal relationship between the intervener and the opponent. There must therefore be a legal relationship between the intervener and the opposing party to the proceedings to which the res judicata effect of the decision extends. This can be assumed in particular if there is a joint and several debtor relationship between the intervener and the opposing party.

The intervener may be joined until the decision becomes final, i.e. also in the context of an appeal, until the time at which the judgement can no longer be challenged by legal means.

Joining the proceedings

The intervener joins the proceedings by means of a written submission to the court, which must identify the parties and the legal dispute, state the reason for the intervention (legal interest of the intervener) in sufficient detail (including the underlying facts) and contain a declaration of joining one of the parties. The court then serves the pleading on the parties to the proceedings.

In addition, the pleading must also fulfil the general provisions for preparatory pleadings pursuant to sections 129 et seq. ZPO, i.e. it must be submitted by a lawyer if the proceedings require representation by a lawyer in accordance with Section 78 ZPO.

The intervention can be withdrawn at any time with the consequence of costs in accordance with Section 269 (3) and (4) ZPO.

Legal status and rights of the intervener

While the intervening party represents his own interests without restriction, the simple intervener may not behave inconsistently with the main party he is supporting.

By joining the proceedings, the simple intervener does not become a party to the proceedings, but may assert means of attack and defence and perform procedural acts, provided that these do not contradict the actions of the main party. The contradiction may arise expressly from the behaviour of the intervener or from the overall behaviour of the main party supported and leads to the invalidity of the action of the intervener. The intervener must accept the situation of the legal dispute at the time of joining, i.e. he cannot, for example, submit applications on his own behalf. He acts in his own right and in his own name, but what he submits is deemed to have been submitted on behalf of the supported party.

The intervening party is not only an intervener, but is also deemed to be a co-contestant of the main party in accordance with Section 61 ZPO. However, the status as a party to the dispute is only fictitious and the intervening party does not become a party to the proceedings. Nevertheless, he may not testify as a witness. It follows from the res judicata effect that the restrictions of section 67 sentence 1 clause 2 ZPO do not apply to the intervening party in the dispute. For example, he may waive the claim, section 306 ZPO, confess in contradiction to the main party (section 288 (1) ZPO) or take procedural action against the will of the main party. However, he may not amend or withdraw the action, file motions on his own behalf or make a declaration of settlement.

Legal effect

According to the intervention effect of Section 68 ZPO, the intervening party cannot contest the correctness of the judgement in any subsequent proceedings against the supported main party; the court is bound by the content of the judgement in the previous proceedings as far as the intervention effect extends. In terms of content, the intervention effect relates to the main elements of the judgement, i.e. all necessary (decision-relevant) factual and legal findings. There is no binding effect on the other, unsupported main party.

The only possible defence in subsequent proceedings relates to the main party's poor conduct of the proceedings, i.e. inadequate submission of the facts or failure to take procedural steps, but is very rarely successful. It presupposes that the intervener was unable to influence the course of the proceedings, for example because he was bound to an irrevocable situation when joining or was not allowed to contradict the main party, and the proceedings would have ended more favourably for him if they had been conducted properly.

However, an objection pursuant to Section 68 ZPO is only possible for the intervening party if res judicata does not extend to him in its entirety.