This session will explore learning (and questions) from a number of open data for accountability projects. (1) The org-id.guide project is creating a collaborative 'register of registers' or organization identifiers, in order to improve the quality of open data about companies, government agencies and charities. (2) The Open Contracting Data Standard describes the need for contracting process identifiers, to tie together all the stages of government procurement and spending. (3) The Beneficial Ownership Data Standard project seeks to capture information on the links between companies and people, finding a global approach to identifying individuals, whilst respecting privacy, cultural and political differences.