What Is Numerosity?

Numerosity is the requirement that a proposed class be so numerous that joining every member as a named party in one lawsuit would be impracticable. It is the first of the four Rule 23(a) prerequisites for class certification.

Why it matters when you file a claim

Numerosity is rarely in doubt in the consumer settlements most people claim from, which often involve thousands or millions of customers. But it explains why class actions exist in the first place: when too many people are affected to name them all, a class action lets the court resolve everyone's claims at once.

How courts apply it

There is no fixed minimum number. Courts look at the practical difficulty of joining everyone. Factors they may consider include:

• ✓The estimated size of the class.
• ✓How spread out class members are geographically.
• ✓Whether members can be easily identified and contacted.
• ✓How small each person's claim is, which affects whether anyone would sue alone.

Many courts have treated a class of around 40 or more as generally large enough, while very small groups often fail, but the answer depends on the court and the facts.

A simple example

If a dozen workers at one small office claim they were underpaid, a court might say they can simply sue together as named plaintiffs. If a retail chain allegedly overcharged customers in every state, the class could number in the millions, and numerosity would almost certainly be satisfied.

Why it rarely comes up in consumer claims

In most settlements that reach the public, numerosity is not a close question. Nationwide products, large banks and big data breaches affect huge numbers of people. Numerosity disputes are more common in smaller cases, such as claims by employees of one company or customers of a regional business. If a case you follow involves a small group, numerosity may be part of why it ends up as a joint lawsuit rather than a class action.

How it relates to other terms

Numerosity sits alongside commonality, typicality and adequacy of representation in Rule 23(a). All four must be met before a court considers the additional tests for money-damages classes.

Large classes mean many settlements you may never hear about directly. SettleScout matches you to open settlements by the brands and services you use, so the big ones don't slip by.