The Money and Pensions Service is an arm’s-length statutory body responsible for ensuring that people in the UK have guidance and access to information to help them make effective financial decisions. In 2016, the service (then the Money Advice Service) was planning to conduct a longitudinal survey that would identify the long-term impacts of debt advice, understand any variance in impacts by demographic, delivery channel and organisation and identify the most effective outcomes that help to ameliorate over-indebtedness. This scoping study was commissioned to inform the optimal design of the subsequent, prospective evaluation by making clear and detailed recommendations for its methodology.