The Rapid Mortality Mobile Phone Surveys (RaMMPS) project is a collaboration among 13 partner institutions and collects data in Bangladesh, Burkina Faso, the Democratic Republic of the Congo (DRC), Malawi and Mozambique. RaMMPS leverages the expansion in mobile phone use in LMICs. Mortality mobile phone surveys can be deployed rapidly and without the need for in-person contact. These key features also make them suitable to field in the context of epidemic outbreaks or other humanitarian crisis situations. Whereas mobile phone surveys are increasingly common, they have not been used in a systematic manner to measure mortality, and many operational and methodological issues remain to be resolved (e.g., acceptability, sampling, survey instruments). The overall goal of the RaMMPS project is thus to develop and field-test methods for collecting mortality data over the phone. RaMMPS studies are (repeated) cross-sectional surveys. Questionnaires were adapted from standard instruments for estimating mortality in surveys and censuses, covering the following topics or modules:Respondent background characteristics and eligibility screening; informed consent; COVID-19 vaccination; mortality modules; household membership and (recent) deaths; parental survival; sibling survival histories; pregnancy/birth histories. The RaMMPS data also includes para-data on call attempts and interviews. Whereas the countries and institutions participating in the RaMMPS project share the same overall objectives, the implementation of the RaMMPS in each of the countries differs in terms of sampling approaches, survey instruments and other aspects. This heterogeneity was by design.