Court Rejects Use Of Affidavits, Continuing Third Circuit's Stringent Ascertainability Requirements

Key Takeaways:

• Courts in the Third Circuit recognize an implicit ascertainability requirement in Rule 23 that many other circuits do not. Although they permit class members to use affidavits to satisfy the requirement, affidavits must be subject to rigorous screening or be supplemented with additional records or reliable and administratively feasible means.

• A recent decision from the Eastern District of Pennsylvania continues that trend, rejecting a putative class defined using class member affidavits and the defendants' customer email lists.

The Third Circuit is one of a few circuits that recognize an inherent ascertainability requirement in Rule 23. Before a class may be certified, plaintiffs in that circuit must establish that "an ascertainable class [] can be defined using objective criteria and determined using reliable and administratively feasible methods."¹ While plaintiffs often rely on defendants' records—such as customer lists or