Uniform Commercial Code (UCC): Primary federal commercial law framework, especially Article 2 (Sales) and Article 9 (Secured Transactions), governing commercial transactions and payment terms

Truth in Lending Act (TILA): Federal law requiring clear disclosure of lending terms and costs to protect consumers in credit transactions

E-SIGN Act: Federal law ensuring the legal validity of electronic signatures and records in commercial transactions

Fair Credit Billing Act: Federal law that protects consumers from unfair billing practices and provides dispute resolution procedures

Equal Credit Opportunity Act: Federal law prohibiting discrimination in credit transactions based on various protected characteristics

State UCC Variations: State-specific adaptations of the Uniform Commercial Code that may affect payment terms and commercial transactions

State Contract Laws: State-specific regulations governing contract formation, enforcement, and remedies

State Usury Laws: State-specific regulations limiting interest rates and defining usurious practices

State Consumer Protection Laws: State-specific laws designed to protect consumers from unfair or deceptive business practices

Federal Reserve Regulation Z: Federal regulation implementing the Truth in Lending Act, providing specific rules for consumer credit

Fair Debt Collection Practices Act: Federal law regulating the conduct of debt collectors and collection procedures

PCI DSS: Payment Card Industry Data Security Standard requirements for handling credit card payments and data

Bank Secrecy Act: Federal law requiring financial institutions to assist government agencies in detecting and preventing money laundering

Bankruptcy Code: Federal laws governing bankruptcy proceedings and affecting default provisions in payment agreements

State Statutes of Limitations: State-specific time limits for bringing legal actions related to payment disputes or contract breaches

State Late Fee Regulations: State-specific rules governing the assessment and limits of late fees and penalties

Data Privacy Laws: Federal and state regulations concerning the collection, storage, and protection of payment and personal information