In today’s connected market, brands are more likely than ever to face negative press that can put their customers relationships to the test. Building and fortifying positive aspects of the brand-customer relationship (such as brand commitment, brand love and self-brand connections) may ward off some of the impact of negative information on customers, but this does not always provide full protection. Even customers who love a brand can turn against it when negative information enters the picture. Considering this, the current study provides an exploratory investigation into a new way to build up customer resilience that would otherwise not be formed simply by strengthening positive attributes of the customer-brand relationship. It argues that brands can strengthen their customers’ immunity to negative brand-related information by using an immunity metric (i.e., merely asking customers to reflect on their immunity makes them more resilient to actual negative information in the future). The construct of immunity has the dual benefit of being diagnostic of relationship strength, as well as acting as an immunizing agent. We test this effect and the process underlying it using three pilot studies, three multi-method studies, and interviews with customers and managers across different contexts. By doing so, the study establishes the theoretical and practical value of customer immunity to negative information and makes critical conceptual and pragmatic contributions to the existing body of customer research.