Federal Securities Laws: Primary federal frameworks including Securities Act of 1933, Securities Exchange Act of 1934, Regulation D (Rules 504, 506(b), and 506(c)), and Investment Company Act of 1940. These laws govern the registration, sale, and trading of securities.

State Securities Laws (Blue Sky Laws): State-specific regulations governing securities transactions, including registration requirements, exemptions, and disclosure requirements that vary by jurisdiction.

Uniform Commercial Code (UCC): Particularly Articles 3 (Negotiable Instruments), 8 (Investment Securities), and 9 (Secured Transactions). These provide the legal framework for commercial transactions and negotiable instruments.

Federal and State Usury Laws: Regulations governing interest rate limitations and restrictions, varying by state with federal oversight. These laws protect against excessive interest rates.

Truth in Lending Act (TILA): Federal law requiring lenders to provide standardized disclosures about credit terms and costs, particularly relevant if the note involves consumer credit.

Consumer Protection Laws: Federal and state-specific requirements including Fair Credit Reporting Act, designed to protect consumer rights in financial transactions.

Tax Considerations: Internal Revenue Code provisions and state tax regulations that affect the tax treatment of promissory notes and their purchases/sales.

Anti-Money Laundering Laws: Bank Secrecy Act and USA PATRIOT Act requirements for preventing, detecting, and reporting suspicious financial transactions.

Investment Advisor Regulations: Investment Advisers Act of 1940 and related regulations governing investment advice and management, if applicable to the transaction.