In re Checking Account Overdraft Litigation, 286 F.R.D. 645

Defendant Comerica Bank is a national bank that implemented a uniform, computerized scheme to maximize overdraft fees.
Plaintiffs Simmons and Mattlage are current/former Comerica customers alleging deceptive and unlawful overdraft practices.
Plaintiffs allege Comerica re-sequenced debit card transactions from highest to lowest, causing more overdraft fees.
The scheme allegedly involved a concealed overdraft policy and a Matrix line of credit that affected all class members.
Plaintiffs seek class certification under Rule 23, with proposed state-law subclasses to address variations across jurisdictions.
The court granted certification after determining the class is ascertainable and common issues predominate across the proposed claims.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the class is ascertainable and properly defined	Simmons/Mattlage: class defined by objective criteria from Comerica records.	Comerica: class lacks objective baseline posting order and requires merits determinations.	Yes; class is readily ascertainable via Comerica’s data and Olsen's methodology.
Do the Rule 23(a) requirements (numerosity, commonality, typicality, adequacy) govern certification?	Plaintiffs show numerosity, commonality, typicality, and adequacy through uniform conduct.	Defendant contends issues are driven by individualized facts.	All Rule 23(a) requirements are satisfied.
Do common issues predominate under Rule 23(b)(3) to justify class certification?	Common proof of a uniform, automated re-sequencing scheme affects all members.	Some defenses and damages issues may be individualized.	Predominance satisfied; common liability issues predominate.
Are subclasses appropriate to manage state-law variations in breach of contract, unjust enrichment, and unconscionability?	Subclassing groups uniform state-law standards to manage variations.	Potential complexity from multiple state laws.	Yes; five subclasses are certified to govern state-law claims.

Klay v. Humana, Inc., 382 F.3d 1241 (11th Cir. 2004) (predominance and commonality standards for class actions)
In re Cardizem CD Antitrust Litig., 200 F.R.D. 326 (E.D. Mich. 2001) (framework for Rule 23 analysis and common questions)
Wal-Mart Stores, Inc. v. Dukes, 131 S. Ct. 2541 (U.S. 2011) (limits on commonality in large class actions; need for common proof)
Rick v. Visa Check/MasterMoney Antitrust Litig., 280 F.3d 124 (2d Cir. 2001) (common questions able to predominate in antitrust class actions)
Allapattah Servs., Inc. v. Exxon Corp., 333 F.3d 1248 (11th Cir. 2003) (jurisdictional/class action considerations; common issues can predominate)
Sacred Heart Health Sys., Inc. v. Humana Military Healthcare Servs., Inc., 601 F.3d 1159 (11th Cir. 2010) (illustrates issues with uniform contracts and class certification)
Kinkel v. Cingular Wireless LLC, 223 Ill.2d 1 (2006) (unconscionability and contract terms; class treatment considerations)