Claim substantiation refers to the obligation of advertisers to ensure that the messages they communicate about their products or services are truthful and not misleading. In practice, meeting this obligation can be very challenging for marketers and their legal counsel. There are several reasons for this. First, the law that governs advertising claim substantiation is drawn from a variety of different legal practice areas and disciplines. Additionally, because advertisers are legally responsible for both express and implied claims, this question of communication and perception can be a crucial first step. Finally, claim substantiation is complicated by the very flexibility of the legal standard. As a general matter, advertisers are required to have a "reasonable basis" for their claims.

The purpose of this handbook is to provide legal practitioners with an introduction to the law, principles and challenges of claim substantiation. The guide provides legal principles, examples and numerous suggestions for further research. Topics such as privacy and promotions are sometimes touched upon, but the handbook's focus is on the legal issues that relate to claims—the express and implied statements made in advertising about a product or service. The handbook draws upon the experience of some of the nation’s leading experts in advertising and consumer protection law and the contributions of attorneys within the Consumer Protection and Advertising Disputes and Litigation Committees of the ABA Antitrust Section. This handbook will assist marketers and their attorneys in navigating the uncertain waters of claim substantiation and help them in evaluating risk and providing sound legal advice on remedies, liabilities and opportunities.