The trial of Payment by Results (PbR) in children's centres was undertaken between September 2011 and March 2013. The objective was to test whether PbR incentivised a local focus on the core purpose for children's centres using a unique "two-tier" model. This two-tier model consisted of a "national" element of commissioning arrangements between the Department for Education (DfE) and Local Authorities (LAs) and a "local" element involving the service and commissioning arrangements between LAs and children's centres. The evaluation of the trial aimed to provide evidence on the impact of national PbR on local decision-making and on what works in terms of the practical implementation of a national PbR scheme. It also sought evidence on on how local schemes were developed and on the conceptual and practical challenges to creating local PbR models for children's centres. (author abstract)