Intervention
The procedural act by which a third party joins an existing lawsuit to protect interests not adequately represented by existing parties.
While straightforward in theory, many businesses fail to actively track obligations tied to this concept - often resulting in missed deadlines, unintended renewals, penalties, or loss of contractual rights.
US Law · For business owners and foundersWhat is a Intervention?
Intervention is the procedural right of a third party who is not an original party to a lawsuit to join the existing litigation. The third party (the "intervenor") seeks to protect their own interests that may be affected by the outcome of the case. Intervention is governed by Federal Rule of Civil Procedure 24 in federal courts and by similar state rules in state courts.
There are two types of intervention: intervention of right (required by law when the intervenor meets statutory criteria) and permissive intervention (allowed at the court's discretion if the intervenor's claim or defense shares common questions of law or fact with the existing case).
In practice, many teams rely on a contract expiry tracking system to stay on top of dates and obligations tied to clauses like this.
Key Elements
Intervention of Right
A third party has the right to intervene if: (1) a statute gives them an unconditional right to intervene; (2) they claim an interest in the property or transaction at issue; (3) their interest may be impaired or impeded by the outcome; and (4) the existing parties may not adequately protect that interest. If all four are met, the court must grant intervention.Permissive Intervention
A court may allow intervention if: (1) the intervenor's claim or defense shares a common question of law or fact with the main case; and (2) the court determines intervention will not unduly delay or prejudice the parties. Permissive intervention is within the court's discretion.Direct and Significantly Protectable Interest
To intervene of right, the third party must show they have a direct interest in the case, not a mere consequential or remote interest. A party whose contract performance depends on the outcome of a lawsuit has a direct interest and can likely intervene. A party affected only indirectly by the ruling generally cannot.Inadequate Representation
The intervenor must show that the existing parties will not adequately protect their interests. If the existing parties' interests align with the intervenor's, intervention may be denied. But if the existing parties' goals differ from the intervenor's, inadequate representation is likely established.Timing
An intervenor must move to intervene by written motion. Intervention can occur at any stage of litigation, but earlier intervention is preferred. The court has discretion to deny late intervention if it would prejudice the parties or delay the trial.Real-World Example
Company A sues Company B for breach of a contract to deliver software. Company C, an intended end-user of the software, is not a party to the A-B contract but has a commercial relationship with Company A that depends on receiving the software. Company C moves to intervene in the A-B lawsuit to protect its interests in ensuring the software is delivered.
Company C likely has the right to intervene if it can show: (1) it has a direct interest in the software delivery (yes - it depends on the software); (2) the A-B litigation may impair that interest (yes - if Company A loses, the software may never be delivered); and (3) Company A may not adequately protect Company C's interests (likely - Company A's goals are to recover damages, not to ensure Company C receives goods). Company C would file a motion to intervene, likely attaching evidence of the relationship and the importance of the software.
This is why many businesses adopt automated deadline tracking to ensure no critical dates are missed before they pass.
Sample Clause Language
Notice of Intervention RightWatch Out For
Moving to intervene too late in the case
Intervention motions filed near trial may be denied as untimely. The court will consider how far the case has progressed, whether docket is crowded, and whether delay would prejudice the original parties. Move early if you believe you should intervene.Assuming a consequential interest is enough to intervene
Being affected by the outcome is not the same as having a "direct interest" sufficient to intervene. For example, if you are a competitor and a lawsuit involving your competitors might indirectly affect you, you generally cannot intervene. The interest must be direct, not merely consequential.Filing an intervention motion without meeting procedural requirements
Intervention motions must be filed as formal written motions with proper notice to existing parties. Do not try to intervene informally or by letter. Follow your jurisdiction's procedural rules strictly.Don't let intervention deadlines catch you off guard
Key dates tied to interventions - renewal windows, expiry cutoffs, notice periods - can easily slip through the cracks when tracked manually. Missing them triggers automatic extensions, penalties, or lost rights. ExpiryEdge tracks every critical deadline and sends automated reminders before they're due - so nothing slips.
Instead of relying on spreadsheets or manual follow-ups, a centralized renewal reminder system ensures every deadline is visible, tracked, and actioned automatically.
How to Use This in Your Favor
Move early to intervene if your interests are directly affected
If you have a direct interest in a lawsuit involving others - such as a contract that depends on the outcome or a transaction that could be impaired - file a motion to intervene early. Early intervention is easier to obtain and gives you a voice in the litigation.Gather evidence of direct interest before moving
Document the nature and significance of your interest before filing an intervention motion. Evidence of contractual relationships, commercial importance, or statutory rights strengthens your motion and makes it more likely the court will grant it.Related Terms
Frequently Asked Questions
What is the difference between intervention of right and permissive intervention?
Intervention of right is mandatory if the intervenor meets all statutory criteria - the court must grant it. Permissive intervention is discretionary - the court can allow it but is not required to. Intervention of right has a higher bar but, if met, is almost certainly granted.
Can a third party appeal a decision denying their motion to intervene?
Yes. A denial of a motion to intervene of right is immediately appealable in many jurisdictions because it affects the third party's right to participate in litigation. A denial of permissive intervention is generally not immediately appealable - the third party must wait until final judgment.
If I intervene in a lawsuit, do I become fully a party to all claims?
Not necessarily. The scope of an intervenor's participation is limited to the claims and issues related to the interest they sought to protect. The court defines the extent of the intervenor's participation based on the facts of the case.